Not sure quite where to post this & it’s going to be quite wordy as well. Apologies in advance.

I have a 2011 Ram 1500 SLT 4WD 5.7 Hemi with 183,000 miles.

These are all the codes I have currently:
-P0301 cylinder 1 misfire
-P0456 evap system leak (I have a small exhaust leak so self explanatory)
-P0153 O2 sensor 2/1 slow response
-P0133 O2 sensor 1/1 slow response
-P0430 Catalyst system efficiency below threshold (Bank 2)

These are the dash lights I have on:
-CEL
-ABS
-TCS
-Service 4WD

The ABS, TCS, and Service 4WD light I believe to be the ABS wheel speed sensor. It was damaged and I haven’t replaced it yet.

I need help with the cylinder 1 misfire. First the symptoms.
-The CEL will only come on/flash only at high speeds/RPMs or if I get on it.

-After the CEL comes on the engine will run rough, vibrate, acceleration will be poor, and when I go to accelerate it feels like the engine is bogged down and acceleration cuts in and out with steady pressure on the gas pedal.

-When coming to a stop the RPM’s will fall out and the truck will be on but my engine will be off. I’ll have to put it in neutral and start it again.

What I have done & had done:
I changed the spark plugs and ignition coil on Cylinder 1 and I did a compression test (normal results) I then took it to a shop to have it looked at they said my drivers side up stream O2 sensor wasn’t plugged in all the way and was flooding my engine. They plugged it back in and sent me on my way. The code came back and I called they said to replace that sensor. So I replaced both upstream O2 sensors just to be safe. The truck ran good until I got on it and the code came back along with the same symptoms. It hasn’t stalled yet but I’m sure it’ll happen eventually.

Let me know if you need any more info/have ideas.

Please help.

 

Did you clear the codes after replacing the O2 sensors? What brand sensors did you install? Exhaust leak shouldn't have anything to do with EVAP system. Small leak is usually seal on the gas cap....

 

I did clear the codes. I unplugged my battery while replacing the O2 sensors. My check engine light was off afterwards. They were NTK sensors. Noted on the gas cap. Thank you!

 

Hhhmmm.... The slow response codes seem kinda strange then...

Another oddity: Problem only presents on large throttle openings..... however, step on the gas hard enough, and the computer goes to open loop, and just ignores the O2 sensors..... How is fuel pressure?

 

I would not expect a poor connection on the oxygen sensor to cause a misfire code or a specific cylinder. A random misfire, maybe. Multiple bank 1 cylinder misfire codes, maybe. An actual misfire (which from your description it does sound like you have) also would not be an expected symptom of an intermittent O2 sensor reading.

Are you sure the coil you replaced was for cylinder #1? Do you have a scan tool that will allow you to monitor the short term fuel trim value while your engine is misfiring under load? Are you comfortable swapping fuel injectors between cylinders, along with swapping the #1 coil with a different cylinder than the injector was swapped with, then seeing if the misfire code follows the coil, fuel injector, or remains on #1?

-Rod