Hi everyone My 06 2.4 is having a serious problem I am getting 3 codes, and the car is not accelerating and making a strange exhaust sound so I think it is limp mode. But even after codes are cleared it still is has these problems

The codes are
P0302 Misfire in cylinder 2
P0171 System lean bank 1
P0326 Knock sensor bank 1

I am hoping these are all related-plugs, coil pack, ??

Any suggestions? Was planning on starting with checking the plugs

 

I’d clean the MAF sensor first.
https://www.obd-codes.com/p0171

 

You could swap spark plug #1 with #2, and swap coil pack #2 with #3. Then wherever the P030X shows up will tell you what is wrong.

I'm guessing the misfire in #2 is leaving unburned fuel causing a rich condition. The computer tries to fix it, causing the P0171 fuel lean.

 

Thanks for the suggestions. Will try both tomorrow.

 

Also have a look at the flex pipe

 

I will check it out but it seemed fine last I checked and there is no exhaust under the hood

 

Where is the strange exhaust sound you mentioned in post #1?

 

Your flex pipe is likely cracking up but not laughing. haha

 

Now I am thinking it may be the flex pipe When I try to accelerate the exhaust note gets loud and sounds like it is under the hood (where the flex pipe is) But at idle with the hood open it doesnt sound like it is leaking and there is no exhaust smell

Is that typical? I did have to replace my engine and trans mounts several years ago so it could have damaged the flex pipe And that could account for all my codes

 

Not sure how that would explain the misfire in #2.