Need help with throwing 2 codes after rebuild

[firefighter196]

I have a 2004 SRT 10, I have installed a set of AC performance heads and cam with M&M headers with vibrant performance high flow cats and BB exhaust. I got the engine fired up and sounds great but i am now throwing a P0051 and P0031 codes. They are both the same (heater control circuit low, bank 1 sensor 1)and (heater control circuit low, bank 2 sensor 1) If anybody has any ideas as both O2 sensors were working great before upgrades and i find it hard to believe both would go bad at exact same time after upgrades. I have only had the engine running for a few mins at a time after rebuild, thanks in advance.

[jaxtk]

I have a 2004 SRT 10, I have installed a set of AC performance heads and cam with M&M headers with vibrant performance high flow cats and BB exhaust. I got the engine fired up and sounds great but i am now throwing a P0051 and P0031 codes. They are both the same (heater control circuit low, bank 1 sensor 1)and (heater control circuit low, bank 2 sensor 1) If anybody has any ideas as both O2 sensors were working great before upgrades and i find it hard to believe both would go bad at exact same time after upgrades. I have only had the engine running for a few mins at a time after rebuild, thanks in advance.

It's very simple, the PCM don't like your upgrades.

[ACtechOPS]

I would look for the obvious. PCM measures the current draw by the O2 heaters. If it is low, you get a fault. Are you sure they are both connected/no damaged wires? The left and right upstream sensors share the same power supply, fuse B11 in engine bay, 20amp - check it. Power goes from the fuse to the ASD (auto shut down relay). Relay does more than one thing but always a possibility. Power goes from ASD to each O2 heater and finally to the powertrain control module. Did you try clearing the code and running the engine again?

[firefighter196]

I checked all fuses in engine bay none blown, i then cleared the codes and started the car. After about thirty seconds at idle the engine light came back on with the same 2 codes. The car has a tune in it from ROE from when i had no mods.

[ACtechOPS]

Here's a link, you can download the digital copy of the shop service manual, it has the wiring diagrams you need. Check for power at the fuse with engine on. Then check for continuity down to the o2 sensors and back to the pcm. I assume you had no idiot lights with the ROE tune prior to heads/cam. Did you get another tune after the work?

https://www.dropbox.com/s/7osdvula7v...ZB-SM.pdf?dl=0

[firefighter196]

I'm just in the process of getting a new tune for this setup do you think by any chance a proper tune for this setup would eliminate this code? Or is that just a pipe dream.

[ACtechOPS]

If you didn't have a code with the ROE tune prior to the mods, I don't think the new tune will solve your issue. That being said, you def need another tune with the mods you have done. Did you do the mods yourself and can you confirm that both upstream O2 sensors are connected?

[firefighter196]

yes i did the mods myself and can confirm the o2 sensors are connected, I will check the drivers side for voltage at the connector in the morning as its the only one i can get at without some major dissasembley. It would seam it has to be something common to both as it would be unusual to lose both o2 at once. I did check the fuses and changed the relay for the horn relay, i know the horn was working. I did find the wiring diagram and will find the pink wire with the grey tracer and see if it has voltage when the key is on.

[viperBase1]

If you didn't have a code with the ROE tune prior to the mods, I don't think the new tune will solve your issue. That being said, you def need another tune with the mods you have done. Did you do the mods yourself and can you confirm that both upstream O2 sensors are connected?

ACtechOPS, what a guy.

[firefighter196]

In checking the resistance on the heater on the front O2 sensors i found an open circuit on both O2s. I checked with an extra one my friend had and it was closed. I also checked my back O2s and found they were both closed, So i think i haave 2 bad O2s in the front but how this happened is a mystery as they were working well before the rebuild. I am hooking up the O2 my buddy gave me on one side on the front and one of my old ones on the other side on the front, I will clear the codes and try firing it up again, if this works it should only set off one code this time on the old O2 side the other side should work normally, this will confirm this is the fix before installing 2 new O2s and damaging them. I will keep you posted and thanks for your help.

[ACtechOPS]

Very strange, but sounds like you are on the right track. If I had a nickle for all the strange coincidences I've experienced...I'd have a bunch of nickles. Keep us posted.

[Jack B]

The chances are that you left off or broke a ground wire. The G2, O2 ground started near the AC compressor, the G3 is probably similar.

[Viper Specialty]

I love solving problems with other vendors parts...

First, do the obvious:

Pull one of the O2's, and start the engine for 15-20 seconds. See if the sensor gets hot. If the sensor is actually warming up, the heaters are working. The Gen-3+ upstream sensors are powered by ASD/fused output, and grounded to the PCM via PWM Driver. There are no grounds to check.

If they are, and you are still having issues, the problem is likely your cam/header combination. Large camshafts, head work, and headers all work towards having a a much cooler warm-up exhaust temperature, and the sensors take too long to respond. This must be accounted for in the tune file, and my guess is that it hasn't been.