Code P0107 - Now odd smell from exhaust

[GhostStalker27]

Had a little scare this weekend - Driving home from the first car show of the year. About half way home I saw a friend down the highway and punched it to catch up. After catching up I let off and decelerating a good amount before getting back on it. As soon as I did the motor sputtered (Limp mode maybe) and lost just about all power. Check engine light came on, oil light, so I pulled over and shut it down. Tried to start her up but nothing, called AAA.


Back at house, ran the obd2. Code - P0107 - Manifold Absolute Pressure/Barometric Pressure Circuit Low Input. She started right up when we got home - but very odd smell coming from the exhaust. Spent the rest of the night cleaning the sensors and intake (pretty dirty). The tow truck guy said it smelt like stale gas? Anyone ever run into a problem like this? I know before the car show I put about 6 gallons in and I wonder if I accidentally put in 89. If that's the case should I just run the car easy for awhile and get 93 in it asap or do I need to flush? Would that cause an odd oder? As far as the smell it's hard to explain (smells a little like gas but not exactly). I read up on the P0107 but nothing mentions odd gas smell from exhaust..Thanks guys


:*(
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[Bugman Jeff]

The MAP sensor measures intake manifold vacuum, and the ECM uses it to help calculate engine load. On most cars, if the MAP goes bad, the ECM likely goes into limp mode where it runs almost entirely off the program, not using the engine sensors to adjust fuel and timing requirements. Because running rich is safer for the engine than running lean, limp mode tunes are often excessively rich. The smell you noticed is probably all the extra fuel it was dumping in.

Stale gas isn't a problem, especially if the car has only been sitting since last fall. Even modern gas takes quite a while to go bad to the point where it won't burn. Just last summer, I pulled a car out of storage that had been sitting four years. The gas and the exhaust smelled awful, but it still ran OK. A partial tank of 89 octane isn't a problem either. If the car pings from low octane, the ECM will pull timing accordingly. Running it easy for the rest of tank, you shouldn't get any pinging anyway. Either way, once you get your problem fixed, you'll burn through the old gas in a few hundred miles.

[Viper Specialty]

The MAP sensor measures intake manifold vacuum, and the ECM uses it to help calculate engine load. On most cars, if the MAP goes bad, the ECM likely goes into limp mode where it runs almost entirely off the program, not using the engine sensors to adjust fuel and timing requirements. Because running rich is safer for the engine than running lean, limp mode tunes are often excessively rich. The smell you noticed is probably all the extra fuel it was dumping in.

Stale gas isn't a problem, especially if the car has only been sitting since last fall. Even modern gas takes quite a while to go bad to the point where it won't burn. Just last summer, I pulled a car out of storage that had been sitting four years. The gas and the exhaust smelled awful, but it still ran OK. A partial tank of 89 octane isn't a problem either. If the car pings from low octane, the ECM will pull timing accordingly. Running it easy for the rest of tank, you shouldn't get any pinging anyway. Either way, once you get your problem fixed, you'll burn through the old gas in a few hundred miles.

Negative.

The Viper ECU will not allow the engine to run with a faulty MAP sensor input. Chances are the sensor is bad, but another possibility is the MAP signal wire contacting a grounding source somewhere- but that is remote compared to the sensor which is not all that uncommon. The MAP signal connection has a pull-up resistor for diagnosing a disconnected sensor, but his code indicates it is pulled Low, not High, meaning either the sensor is outputting low or the signal is being pulled to ground somewhere.

Also, he has a 99, which means it has no knock sensors. I would suggest taking it easy on the car, and when you get about a half tank, top it off with 93+ and then take it easy until you burn all the way through that. Be careful of higher loads in higher gears, its VERY easy to hit high loads in 5th or 6th.

I cannot comment on the odd smell, but it most likely is related to the catalytic converters and temperature, as if the MAP load was incorrect, the fueling would also be incorrect.

[GhostStalker27]

Ah ha that makes sense, probably just a safety protocol from the ECM. So now I need to determine if my MAP sensor is bad, or just dirty. Thanks Bugman, very helpful

[GhostStalker27]

Negative.

The Viper ECU will not allow the engine to run with a faulty MAP sensor input. Chances are the sensor is bad, but another possibility is the MAP signal wire contacting a grounding source somewhere- but that is remote compared to the sensor which is not all that uncommon. The MAP signal connection has a pull-up resistor for diagnosing a disconnected sensor, but his code indicates it is pulled Low, not High, meaning either the sensor is outputting low or the signal is being pulled to ground somewhere.

Also, he has a 99, which means it has no knock sensors. I would suggest taking it easy on the car, and when you get about a half tank, top it off with 93+ and then take it easy until you burn all the way through that. Be careful of higher loads in higher gears, its VERY easy to hit high loads in 5th or 6th.

I cannot comment on the odd smell, but it most likely is related to the catalytic converters and temperature, as if the MAP load was incorrect, the fueling would also be incorrect.

Thanks VS, I have no cats btw. I'll check the voltage tonight. The car is running what seems to be normal now, and the smell is less strong than it was when I initially started it.

[Coloviper]

Same exact code on my 96' when I changed to headers. O2 sensors were bad (slow) and had to put new 02 sensors in with a different range. Problem solved!

[GhostStalker27]

The voltage reads 5, when I plug in the Map sensor it drops to 4.8 volts. Is this typical or a sign that the MAP sensor needs replacing?

[GhostStalker27]

Took the car down the street today, she was running really rough, not before long I broke down and had to pushed it home. So I picked up a new MAP sensor and it still runs rough -I'm getting the same readings as the old MAP sensor (4.8 volts). So I guess I'm left with either fault in the wiring somewhere, a bad PCM, failing fuel pump, compression issue or possibly a timing belt.

Are there symptoms I should be looking for that would confirm or eliminate any of those possible causes? Thanks again

- - - Updated - - -

Same exact code on my 96' when I changed to headers. O2 sensors were bad (slow) and had to put new 02 sensors in with a different range. Problem solved!

What symptoms did you have before changing out the O2 sensors?

[GhostStalker27]

Just so I don't mess anything up.. in order to test the MAP sensor ground - I'm suppose to take multi-meter's red probe and attached to battery + and the black probe and attach to ground wire? Does this sounds right? I don't want to accidentally damage the PCM. I understand it's suppose to read at 12volts. Is there a better way to test this? Thanks

[Bugman Jeff]

Just so I don't mess anything up.. in order to test the MAP sensor ground - I'm suppose to take multi-meter's red probe and attached to battery + and the black probe and attach to ground wire? Does this sounds right? I don't want to accidentally damage the PCM. I understand it's suppose to read at 12volts. Is there a better way to test this? Thanks

No, if I'm reading you right, that will create a dead short from the battery to ground through your multimeter. It will be exciting, and smokey(and possibly explodey, depending on your multimeter). To test a ground, your multimeter should be on one of the Ohms settings. With the car off, touch one probe to the ground pin, and the other to a know good ground(any bare metal parts of the engine, any of the ground studs, etc.). With no probes touching, your meter should have no reading. All you're doing when checking a ground is looking for continuity between the pin and ground.

[GhostStalker27]

Ok, so I noticed that the ground wire going to the MAP sensor is black with a blue stripe. I also installed unitrax speedo calibration box last year which splices into a black wire w/ blue strip that was down next to the PCM. Has anyone installed one of these and can confirm this is the same wire? Has anyone heard of a this map sensor issue happening after installing a calibration box?

No, if I'm reading you right, that will create a dead short from the battery to ground through your multimeter. It will be exciting, and smokey(and possibly explodey, depending on your multimeter). To test a ground, your multimeter should be on one of the Ohms settings. With the car off, touch one probe to the ground pin, and the other to a know good ground(any bare metal parts of the engine, any of the ground studs, etc.). With no probes touching, your meter should have no reading. All you're doing when checking a ground is looking for continuity between the pin and ground.

Maybe I'm explaining it wrong - I got it from this ("map sensor test 3") ->http://easyautodiagnostics.com/chrys...gnostic-test-2

[My98RT10]

...
Maybe I'm explaining it wrong - I got it from this ("map sensor test 3") ->http://easyautodiagnostics.com/chrys...gnostic-test-2

I think the description in the link is not incorrect. Measuring the ground connection of sensors is typically a bit more tricky than just measuring resistance between sensor's ground pin and chassis ground. Reason is, that often PCM provides the ground to the sensor, so there is some active component in between and you don't wanna blow your PCM I guess.

Do you have the Powertrain Diagnostics Procedures book of your modelyear? There are a couple of more tests described for the MAP sensor, which might be useful to further isolate the issue.

[GhostStalker27]

Do you have the Powertrain Diagnostics Procedures book of your modelyear? There are a couple of more tests described for the MAP sensor, which might be useful to further isolate the issue.

I don't

[GhostStalker27]

I installed a calibration speedo box last year. I think this may be part of the issue or the issue entirely. What are my best ways of testing or fixing this(if you agree it's probably the culprit)? Thanks

Speedo Box
IMG_20150419_154824.jpg



Wire coming from MAP sensor (black w/ blue stripe):
IMG_20150419_155030 copy.jpg



Wire tapped into from Speedo Calibration Box (black w/ blue stripe):
IMG_20150419_154925 copy.jpg



Instructions(in the instructions it says to splice into the sensor ground):
Speedo1.jpg

[challenger]

I installed a calibration speedo box last year. I think this may be part of the issue or the issue entirely. What are my best ways of testing or fixing this(if you agree it's probably the culprit)? Thanks

Speedo Box
IMG_20150419_154824.jpg



Wire coming from MAP sensor (black w/ blue stripe):
IMG_20150419_155030 copy.jpg



Wire tapped into from Speedo Calibration Box (black w/ blue stripe):
IMG_20150419_154925 copy.jpg



Instructions(in the instructions it says to splice into the sensor ground):
Speedo1.jpg

I spliced into the black/light blue wire for my sensor ground at the PCM. But I have a yellow box calibration box. They look the same but it is yellow and I can adjust it myself. It's only been in for about a week now with no problems. Not sure if that helps or not. Didn't know it had anything to do with the MAP sensor.

[GhostStalker27]

I spliced into the black/light blue wire for my sensor ground at the PCM. But I have a yellow box calibration box. They look the same but it is yellow and I can adjust it myself. It's only been in for about a week now with no problems. Not sure if that helps or not. Didn't know it had anything to do with the MAP sensor.

Its the same one, mines just black..says yellowbox on it, I can adjust it, etc. I'm gonna rewire everything tonight and see if it fixes the problem - if this is the issue.. I'm surprised I never came across someone else with the same issue.

[Coloviper]

Well I was experiencing the same limp mode barely running, pedal the car home with the gas pedal as you. Flooding, dying, etc. I put in new O2 sensors, reset everything with a battery change (took the opportunity as mine was old) went through the ECM relearn process and never had an issue since. Car has never run so well as it does now.

[challenger]

Its the same one, mines just black..says yellowbox on it, I can adjust it, etc. I'm gonna rewire everything tonight and see if it fixes the problem - if this is the issue.. I'm surprised I never came across someone else with the same issue.

they sent me Viper specific instructions. They might be on there web site or let me know maybe I can help.

[GhostStalker27]

Well I was experiencing the same limp mode barely running, pedal the car home with the gas pedal as you. Flooding, dying, etc. I put in new O2 sensors, reset everything with a battery change (took the opportunity as mine was old) went through the ECM relearn process and never had an issue since. Car has never run so well as it does now.

Limp mode can go on for many reasons, were you getting a p0107 code? Because if not, we probably went into limp mode for different reasons.

they sent me Viper specific instructions. They might be on there web site or let me know maybe I can help.

Mine too. I attached them above.

[My98RT10]

....

Maybe I'm explaining it wrong - I got it from this ("map sensor test 3") ->http://easyautodiagnostics.com/chrys...gnostic-test-2

So, did you do the test described and if so, what was the result? As it says there, if you measure 11-12 Volts when switching ignition on, you can be pretty sure that PCM provides a good ground.

[Coloviper]

I can only write I threw the exact same code number so many times here! Best of luck to you, as nothing more I can help you with, then what I posted. Hope you get it sorted out.

[GhostStalker27]

So, did you do the test described and if so, what was the result? As it says there, if you measure 11-12 Volts when switching ignition on, you can be pretty sure that PCM provides a good ground.

I haven't - I can't figure out how to do it safely and I don't want to take a chance on destroying something like PCM.

The diagnostics test says...
"The PCM is the one that provides this ground internally... so be careful and don't accidentally or intentionally apply power (12 Volts) to this circuit or you'll fry the PCM.

Step1. Volts DC mode
Step2. Probe the ground wire with the BLACK multimeter lead.
Step3. Now, with the RED multimeter lead, probe the battery positive terminal."

Isn't that applying power to it? I dunno, I don't know jack about this stuff and even after researching every night for a week I still feel like I know nothing.

[My98RT10]

....
Isn't that applying power to it? I dunno, I don't know jack about this stuff and even after researching every night for a week I still feel like I know nothing.

No, you will not apply power to PCM by connecting the voltmeter this way. But it is very crucial to switch it into volts mode and not into amps or ohms mode! It's basically like measuring the voltage of your battery with the difference that you connect the black probe to the ground pin of the MAP sensor connector instead of the minus pole of your battery directly.

But if you feel uncomfortable doing it you may want to ask someone who has done it before.

[GhostStalker27]

No, you will not apply power to PCM by connecting the voltmeter this way. But it is very crucial to switch it into volts mode and not into amps or ohms mode! It's basically like measuring the voltage of your battery with the difference that you connect the black probe to the ground pin of the MAP sensor connector instead of the minus pole of your battery directly.

But if you feel uncomfortable doing it you may want to ask someone who has done it before.

I think I'll try tonight. Just about everything on these multimeters looks Chinese to me.

This is the multimeter I have, is DCV that's selected in the picture the mode I want to use? There are so many V's and DC's O's I dunno what the hell I'm looking at haha
Screen Shot 2015-04-22 at 9.08.46 AM.jpg

[My98RT10]

Yes, DCV should be correct.