Emissions OBD Catalyst not ready questions

[Blue96GTS]

Short-ish version of a longer story:

Need to pass Colorado Emissions to renew my plates. For my '96, Colorado only hooks your car to OBD to check things out, no dyno or tailpipe sniffing is done. As long as all of the emissions circuits have checked in, you pay your $25 and you are down the road. Last I did this 2 years ago, the car passed without issues.

Last week I took the car to get checked, and she failed due to the "Catalyst" light blinking - indicative of a Catalytic Converter issue. Hmmm. The car has been running great, but did have a recent issue traced to a faulty (cracked) spark plug, causing a miss, but otherwise has been running well. I haven't disconnected any battery power or reset anything recently to make things "not work".

Another random separate occurrence involved finding some honeycomb shaped object lying in my driveway a couple of months ago. Although I'm also a bee-keeper, this was not from my bees, but looked to be parts of a catalytic converter - just the insides....

Putting these 2 separate events together made me wonder if I actually have a catalytic converter, since I didn't think I did - and I told Dan Lesser to give me a tune without a Cat. It's been about 6 years since I had exhaust work done, and perhaps I was mistaken.... I started some self doubt, and began to think that my bogus information has caused me problems, including somehow blowing out my cats!!!

So, last night I tore the drivers side exhaust apart to verify what was actually in the car. The good news is that my memory was correct - I have headers, NO cats (just a "resonater chamber"), and an Aero muffler (sound is good and loud!).

Some of my mystery is solved, like the cat-parts on the driveway. Although I don't know where they actually appeared from, they cannot be from the Viper as I don't have cats....

My original problem still remains - passing emissions. I should also note that I have all 4 O2 sensors installed, the rear 02 sensors are stubbed out from the exhaust using the "spark plug arrestor" trick. This all seemed to work fine/dandy last time with emissions, but this time the catalyst light is blinking, blinking, blinking, blinking...

So, my quandary. What to do to pass emissions? I don't have cats, nor do I want them. Reading up a bit in the service manual (and no wires going to the cats) leads me to believe the cats aren't an actual "managed" circuit, but feed their "ready state" off other findings/readings. No other codes are showing up in OBD-land. O2 sensors are relatively new. Car is in great shape, has a recent new wires, plugs, etc...

The recent spark plug issue could be to blame, as the mis-behaving spark plug caused general poor performance and additional backfires out of the exhaust. The spark-plug incident happened about 100 miles from home after the Viper trip to Vegas - perhaps I've not given the engine enough "cycles" to over come what was going on when it was misbehaving??

Perhaps it's the custom tune I put on the car from Dan Lesser?? I told him (apparently correctly) that I don't have cats, and the tune he gave - and that I've been running for about 2 years - seems to have worked great! Perhaps I need to go back to the stock tune to pass emissions, and then put the custom tune back on?? I'm not sure if I had his tune on the car before or just after the last time I got emissions checked.

Or, perhaps it's something else altogether...?? Looking forward to hearing any advice you might have - other than moving out of a county that requires emissions...

FWIW, here's 2 pictures of the exhaust. Smallish object on top of the pipes is part of a cat from somewhere... Apparently not the Viper.

Thanks for your time.

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[LifeIsGood]

Are you saying that part of the exhaust in the picture is hollow?

[dave6666]

Dan's been tuning my car for getting close to 10 years now. We've had plenty of discussions regarding emissions, although not your exact issue, and the bottom line is, if you try to cheat or trick a PID loop tied to the basic emissions readiness status, you will never trip to a ready status.

Now that is not your problem now, but if you attempt to do that as a long term solution, you will never pass. We have some things done to my tune that will never allow me to pass. Basically, the 2-bar MAP sensor and the fact it conflicts with other emissions components that we have to turn off. Hence I will never trip the emissions readiness monitor. I get my car inspected out of town, so I have options.

You did not mention a CEL, but instead a flashing O2 light. I'm not familiar with how to reset that. Have you tried to clear that? However it is done? BTW, I have no cats either, also have the oil foulers on the rear, and also have no O2 sensor issues. My tune related crap is not the O2 sensors. So it sounds like your O2 sensor issue may be temporary.

Lastly, the correct way to perform a drive cycle for a Chrysler is bizarre. You may need to make sure you do this after you clear all the issues. Here is a good read on a Chrysler drive cycle.

https://www.justanswer.com/chrysler/34h2n-tried-pass-emissions-test-four-times-check.html#re.v/287/

[Camfab]

So much doesn’t make sense here. The picture of that exhaust is definitely a CAT, so did you punch it out, or are you likely misidentifying a part due to a lack of knowledge?

[dave6666]

It's not unheard of for a CAT to self destruct without hammers and long screwdrivers involved.

[AZTVR]

So much doesn’t make sense here. The picture of that exhaust is definitely a CAT, so did you punch it out, or are you likely misidentifying a part due to a lack of knowledge?

Agreed. Is that catalytic converter being called a resonator just because it appears to be hollow. It seems very likely, that the piece sitting on top of it came from inside it. I would want to know if the converter from the passenger side is hollow or does it still have its core in it or is it broken up and blocking exhaust flow?

[Blue96GTS]

OK, gotta admit to being a dumbass here. Amazing none of you used that term in your reply - I definitely would have deserved it!

Dug out the receipt from the exhaust work 5 years ago, and line #1 is 2 catalytic converters, as you correctly identified. Not sure how or why I thought I was cat-less all these years, but I was wrong.

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I guess this also explains my magically appearing catalyst parts on the driveway. Even Achem would have called me out on this one. 2+2 usually equals 4.

Whatever I did wrong, I did it good. A visual inspection of the inside of that blown-out cat reveals nothing left on the inside! Guess I'll have a look at the passenger side.

So, on to the next dumbass dilemma. Looks like I need new cats, but I seemed to have F'ed up in regard to the tune I requested from Dan. I'm certain I told him I was cat-less for tune purposes. Seems like a combination of cats with a cat-less tune, combined with anti-foulers installed on the rear O2 sensors is just trouble waiting to happen. Seems I'll be right back in the same seat eventually. Attempts at remembering how exactly I got to this point are obviously fuzzy, but I'll assume whatever I was up to allowed me to pass emissions at the time and the rest was history.

Seems I need to replace cats, or I won't pass emissions. Can I keep/run the tune I have from Dan, or is this excessively lean and detrimental to the engine? Do I really need the spark-plug anti-foulers for the rear O2 sensors??

Let the beating commence! Thanks!!

[Viper Specialty]

The answers are all obvious:

1. The tune supplied does not alter cat function, and you would have been told to use non-foulers if there were no cats- which is what happened seemingly. Lean conditions do not damage converters, rich conditions do- and only under certain circumstances that are very excessive and oscillating.

2. You had a broken plug. This causes a misfire. Blinking CEL indicates cat-damaging misfire in progress.

3. Converter material on ground indicates cat damaging misfire [duh].

4. Those converters are Ceramic, and are more prone to failure in the first place.


Replace the converters and make sure the ignition system is good to go.

/End thread.

[Blue96GTS]

Thanks Dan (and everyone else) for the input and patience.

The ceramic material on the ground happened before the plug misfire issue, and my lean question was more of a concern about preserving the engine than the cats. Regardless - I see the logic of the failure events, I understand the errors in my ways, and have a path of enlightenment for correction.

I'll continue to run the custom tune provided, with the new cats that await my future. I'll not use the anti-foulers on the rear O2 sensors. Provided everything else is OK, I should be able to pass emissions and motor happily down the road.

[Camfab]

Just make sure you get a quality metal matrix CAT. Kooks sells what appears to be a high quality high flow CAT.., called Green CATS. Something to check out.

[Blue96GTS]

Thanks for the scoop on Green CATS. Here's what I've found, FWIW - hoping this information might benefit someone else.

I did not realize this, but apparently Catalytic Converters have been in use in (some) automobiles since the late 1800's. "Cats" also do a lot of work to keep factory smokestacks from bellowing particulates into the atmosphere. History lesson for the day. On to why we care...

The substrate, or foundation of the inside of our cats, seem to come in 2 main types - Ceramic Monolith (honeycomb object in the picture above), or a Metallic Foil Monolith. Ceramic cats are generally cheaper to produce in mass quantities, and generally seem to be OK for the average vehicle. Metallic Cats (as CAMFAB recommends) are generally more expensive to produce than their Ceramic counterparts, but may hold up better to high heat and exhaust pressures found in performance applications. Based on my pictures above, and perhaps somewhat due to my fault, I'd say my ceramic cats did not hold up so well... Ceramic cats seem to run about $150/cat while the Metallic cats seem more in the $400+ range/cat.

The Kooks Green Cats reference themselves as a "GESI" cat. A bit of research reveals that Global Emissions Systems, Inc - GESI, is a Canadian manufacturer of Emissions systems for the overall industry - cars, trucks, small and big engines of all types. Seems a GESI cat would be a cat manufactured by this company, sold in partnership with other vendors including Kooks, which historically is a go-to vendor for exhaust systems. Another vendor of GESI cats, also recommended to me, is Vibrant Performance. Kooks seems to have 1 hi-flow GESI cat, supporting "hi-horsepower applications, including forced induction". Vibrant seems to have 2 levels of GESI cats - High Output (HO cats) supporting 350-500 HP N/A applications, and an Ultra High Output (UHO) cat supporting more HP (500-850) including forced induction motors. Seems the Kooks cat is the same as the UHO Vibrant cat, but I cannot confirm this fact.

Both the Kooks and the Vibrant cats can be found at Summit/Jegs.

I haven't done any cat work yet, so nothing new to report on the emissions front.

[AZTVR]

Thanks for the scoop on Green CATS. Here's what I've found, FWIW - hoping this information might benefit someone else.

I did not realize this, but apparently Catalytic Converters have been in use in (some) automobiles since the late 1800's. "Cats" also do a lot of work to keep factory smokestacks from bellowing particulates into the atmosphere. History lesson for the day. On to why we care...

The substrate, or foundation of the inside of our cats, seem to come in 2 main types - Ceramic Monolith (honeycomb object in the picture above), or a Metallic Foil Monolith. Ceramic cats are generally cheaper to produce in mass quantities, and generally seem to be OK for the average vehicle. Metallic Cats (as CAMFAB recommends) are generally more expensive to produce than their Ceramic counterparts, but may hold up better to high heat and exhaust pressures found in performance applications. Based on my pictures above, and perhaps somewhat due to my fault, I'd say my ceramic cats did not hold up so well... Ceramic cats seem to run about $150/cat while the Metallic cats seem more in the $400+ range/cat.

The Kooks Green Cats reference themselves as a "GESI" cat. A bit of research reveals that Global Emissions Systems, Inc - GESI, is a Canadian manufacturer of Emissions systems for the overall industry - cars, trucks, small and big engines of all types. Seems a GESI cat would be a cat manufactured by this company, sold in partnership with other vendors including Kooks, which historically is a go-to vendor for exhaust systems. Another vendor of GESI cats, also recommended to me, is Vibrant Performance. Kooks seems to have 1 hi-flow GESI cat, supporting "hi-horsepower applications, including forced induction". Vibrant seems to have 2 levels of GESI cats - High Output (HO cats) supporting 350-500 HP N/A applications, and an Ultra High Output (UHO) cat supporting more HP (500-850) including forced induction motors. Seems the Kooks cat is the same as the UHO Vibrant cat, but I cannot confirm this fact.

Both the Kooks and the Vibrant cats can be found at Summit/Jegs.

I haven't done any cat work yet, so nothing new to report on the emissions front.

I went with the metallic cats recommended by Jon at Partsrack so that I knew what type I was getting and they had a good history with the Viper application.

[Camfab]

I would call Kooks directly and talk about your application. Additionally I’d ensure you don’t have any tuning gremlins that Dan L. could sort out for you. Realize that no aftermarket unit is as good as a OEM CARB certified unit.

[Blue96GTS]

Status update:

Finally got off my ass and replaced the cats. Went with the Kooks Greencats, which in fact are stamped GESI on the other side. Not that Kooks ever responded to my multiple emails and questions, but these appear to be the same as the Vibrant cats only cheaper. Happy to report that after a couple of engine cycles, OBDII was no longer complaining and she passed our emissions exam. World record of 50 minutes got me thru emissions AND the DMV for plate renewal. I was pretty happy to have a legal car back, just in time for a local club drive to Utah, which she happily obliged without complaint. Apparently I hadn't noticed how progressively louder she had become, but she's a bit quieter now in a good way. Still plenty of rumble and a nice deceleration burble. No noticeable loss of power according to my SOTP meter.

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[Blue96GTS]

Mopar was happy the 2 new cats were of no concern to him personally.

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[Blue96GTS]

Thought I'd give an update, almost 3 years later.

Time, again, for an emissions test. About a month or so ago, I drug the car out of winter hibernation (late sleeper) and started to get ready for Viper Rendezvous. Violet seemed to be running well, no dash lights warning me of trouble, so one day I was off to the "Air Care" people for an emissions test. My mistake was not hooking my OBD scanner to the car before I went, as the "cats not ready" followed by "come back later" was the message from the Emissions station. Fine... As a side-note, I had to take my tshirt off my body, and use it as a mask while waiting for this to go on, since I didn't bring a mask with me to the mostly-outdoor testing station...

Off to Hastings where the car ran great all weekend. Thought surely some "not ready" codes would be cleared by the time I returned... Not true! Apparently hauling ass around the track is not the same as the drive cycle steps linked in an earlier thread from Dave.

Took the car out last night for a country cruise, adhering to that whole "speed limit" thing, which is totally overrated IMHO. However, the CAT and the O2 codes cleared up, leaving the Heater code remaining. According to the Chrysler docs, this would not clear until the next drive cycle.

Sure enough, today I went out and started Violet up - all emissions systems reported "ready", Emissions light on the scanner went green, and off I went to the air care station where she passed with flying colors. Well, she passed anyway. Quick stop at the DMV, where COVID has done wonders for customer satisfaction and 10 minutes later I'm legal again. A successful 2 hours spent renewing her freedom to roam the highways, including an upcoming Viper club trip to Ouray CO for the 4th of July.

Lessons learned are thus:

1.) I'm successfully running headers, 1 set of Green Cats (still apparently working OK), up/down stream O2 sensors connected, "resonators", and a Dan Lesser tune (thanks Dan!). The car passes CO emissions, which is simply an OBD check, no dyno or sniffing required.

2.) Hook your scanner up to OBD before you head to the emissions station to ensure all emissions systems are in a "ready" state. I'm pretty sure I've learned this a couple of times now...

3.) "Drive it like you stole it" is not the best methodology for clearing Not Ready codes. Follow the Drive Cycle directions outlined in the previous thread attachment.

4.) If possible, plan ahead and try to hit up some of the mobile testing stations before your tags expire. You may not have to worry about codes and whatnot. I believe CO requires 2 passes of a station, cannot be the same day but must be within 30 days of each other, and before your tag expiration window. Air Care Colorado web site has mobile testing stations listed for your area.

Good luck with your emissions woes.

[Viper GTS-R]

If you time it right, after your code clearing drive cycle you have about a 5-10 mile buffer before the light comes on again. With my last Viper I had a heck of a time getting the cel to stay off. After a few drive cycles and learning the timing, I went for my test, passed, and as I drove out of the parking lot the cel came back on. Lol. Now no more emission testing in Ontario - yippee ������