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Discussion Starter · #1 ·
It keeps popping up the P0174 code and I keep smelling gas and rotten eggs . It is back firing and bucking like it’s running out of gas. I have replaced the entire entire exhaust system, fuel system minus the canister, fuel injectors, spark plugs, ignition coil, Throttle body sensor , cam shaft sensor, crank shaft sensor MAP sensor . It does really bad if I get on the highway but I can manage to get around town sort of . Can anybody help ? If it’s the PCM does anybody know a good place to get one.
 

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It keeps popping up the P0174 code and I keep smelling gas and rotten eggs . It is back firing and bucking like it’s running out of gas. I have replaced the entire entire exhaust system, fuel system minus the canister, fuel injectors, spark plugs, ignition coil, Throttle body sensor , cam shaft sensor, crank shaft sensor MAP sensor . It does really bad if I get on the highway but I can manage to get around town sort of . Can anybody help ? If it’s the PCM does anybody know a good place to get one.
My first suspicion would be a bad upstream O2 sensor, and I don't see that in the list of parts you replaced. Especially if that problem only starts once the engine starts to warm up since the PCM doesn't refer to the O2 sensors when the engine is cold. If you replaced it, did you replace it with an NTK brand? Bosch and store brand O2 sensors commonly cause problems/don't work right in our Wranglers.
 

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Discussion Starter · #5 ·
It keeps popping up the P0174 code and I keep smelling gas and rotten eggs . It is back firing and bucking like it’s running out of gas. I have replaced the entire entire exhaust system, fuel system minus the canister, fuel injectors, spark plugs, ignition coil, Throttle body sensor , cam shaft sensor, crank shaft sensor MAP sensor . It does really bad if I get on the highway but I can manage to get around town sort of . Can anybody help ? If it’s the PCM does anybody know a good place to get one.
 

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You reposted the same post, did you intend to add more information like if you also replaced the O2 sensors?
 

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Discussion Starter · #7 ·
I replaced both mini cats both O2 sensors except one of the O2 sensors went bad . These are all OEM parts . There is black crud soot coming out my pipe and it looks like there maybe a leak in the pipe near the 3 catalytic converter and muffler . Ever since they replaced the exhaust system and fuel injectors and spark plugs my jeep hasn’t been right . They said fuel system so I paid for that and it didn’t fix it , they said all these sensors and that didn’t do it either . Now they are saying it’s that canister or PCM but before I continue throwing money at a problem, I just want to make sure that that’s the problem. Honestly this is why I start school in January to learn to be a certified jeep mechanic. That way I may not know but at least I’ll have the tools to fix it and figure it out. 😁
 

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Discussion Starter · #8 ·
My first suspicion would be a bad upstream O2 sensor, and I don't see that in the list of parts you replaced. Especially if that problem only starts once the engine starts to warm up since the PCM doesn't refer to the O2 sensors when the engine is cold. If you replaced it, did you replace it with an NTK brand? Bosch and store brand O2 sensors commonly cause problems/don't work right in our Wranglers.
Replaced with OEM
It was done at a dealership hey I want to say thank you for responding trying to help me .
 

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Not sure that it will help us much in this case, but what year, engine do you have?
 

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Well, the 04s aren't known for PCM issues.

I can't see the canister causing the problem either.

And you have a lean code but it's dumping gas and running rich.

The only thing I can think of is a bad coolant temp sensor telling the PCM it's cold. What does the temp gauge show?

You've replaced all the other usual suspects.
 

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97' TJ 2.5L 5spd w/ Kumho Road Venture AT51 LT 31X10.50R15
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The dreaded P0174 code, and in other cases it's sister code P0171, has driven a lot of people to drink. Some people will jump to the conclusion the O2 sensor is bad when they first see it illuminating the check engine light. That is far from what a first diagnosing response should be as the O2 Sensors are actually doing their jobs. They are telling you there is something wrong with the system and it needs to be addressed. Don't get me wrong, If the problem has not been fixed, and the more you drive it, you'll eventually be replacing the O2 sensor.

Now, as for your jeep, the P0174 code is a hint on where to start looking for problems. The P0174 code points to Bank 2, Sensor 1,(Upstream), before the Cat. That would be where Cylinders 4 ,5, and 6 are at. Check for Vacuum leaks around the intake gasket, along with a possible cracked intake, pinched or missing Injector o-rings, bad Injector(s) and/or wiring issues, cracked or missing exhaust manifold gasket and/or manifold itself being warped or cracked.
(I know you've had all new injectors installed, but I've ran across new injectors that were bad.)

If all that checks out, then start looking at the other side where Cylinders 1, 2, and 3 are at. Check the throttle body gasket, Mass Air Flow sensor, Fuel pump pressure, and the Closed Crankcase Ventilation (CCV) System with all its related parts.

Hopefully you'll find your issue soon.
 

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The dreaded P0174 code, and in other cases it's sister code P0171, has driven a lot of people to drink.

Check the throttle body gasket, Mass Air Flow sensor, Fuel pump pressure, and the Closed Crankcase Ventilation (CCV) System with all its related parts.
Looking for the Mass Air Flow sensor can drive one to drink as well.
 
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