I have had SES light for about two weeks, diagnosis says: p0171 lean bank 1
p0174 lean bank 2
p0300 cylinder misfire
Present time data shows every cylinder missing, but my car runs fine. I was thinking that my cam could be why it is showing a lean condition. I am not real sure what is setting misfire codes, and need some help.

 

Did this happen since you put a cam in??

I take it you have access to scan data? What are your ltrims averaging (look at cells 1-19 and average them). Run your rpm's up above 1200 and see if your misses drop off. (random miss-fires at idle with a cam is not uncommon)

Mark

 

I have had my cam in for about a year now. My sig insn't up so I'll list my mods: lid, maf ends, Mac w/ory, hotcam. I don't have access to atap right now, my friend is a tech and ran the diagnostics at his shop on his snap-on tools diagnostic computer. If the misfires are common why do I have the codes for my left and right banks being lean?

 

So the car was running ok after the cam install and these problems are relatively new? Is this correct?

If this is the case, let's find out some more. How bad are the misses (how many counts). What are the ltrim readings for both banks at idle and at cruise?

I know, you're going to need to run a good scan log. If you can get to your friend again, the Snap-on MT2500 can do this for you and you can then download it to a PC.

Also, I'm assuming your buddy cleared the codes, did they come right back??

Mark

 

Yes these problems are new. From about a week and half ago the miss counts were anywhere from 7000-9000 on every cylinder. I belive my ltrims were running around 850.

 

Yes the codes were cleared and they came back in about 15min.