p0305 & p0171

[scott_gunn]

P0305 is misfire in cylinder #5.
P0171 is system lean in bank 1.

The engine in question is the 4.0 SOHC in a 98 Explorer Sport. I've done some searching about the 00M12 ONP and whatnot, and I'm not sure if that's the fix I need. Besides, I have somewhere around 72,001 miles so I wouldn't be covered. When those o-rings go bad, it seems to throw both P0171 and P0174. I haven't had P0174. The car is idling rough and misfiring like crazy under acceleration.

I thought about changing the plug and wire for cylinder 5, but a bad plug or wire wouldn't explain the lean condition on bank 1, would it?

My IAC has been making noise intermittently as well, but I don't see how a problem with it (or the MAF) would only affect cylinder 5.

Any suggestions?

Thanks,
Scott

 

[yob_yeknom]

If cylinder 5 is on bank 1, I dead injector could cause both of those problems.

If only one part of the o-ring goes bad, it can also make only one bank run lean.

 

[scott_gunn]

I could try some injector cleaner I guess.

By the way, this all started happening while towing a trailer from Mississippi to Florida (a 10 hour drive). It started making a rattling noise during acceleration first. Then, the misfires started shortly after that, but I was able to limp home by shifting manually (to keep the rpms about 2k) and accelerating very gently.

I think my best course of action may be to take it to the devil, err, I mean dealer and see if I can get the 00M12 and 01M01 work done, as well as a new IAC.

Any other suggestions?

Thanks,
Scott

 

[scott_gunn]

Oh, I forgot to mention something else I found. There is something right underneath the IAC that has 2 hoses coming into it, and an electrical plug with a few wires. One of the hoses was disconnected. I reconnected it but it didn't make any difference. Does anyone know what this part is?

 

[scott_gunn]

So, no one else has an opinion? Bad injector or leak?

Does anyone know what the thing is that's right underneath the IAC with 2 hoses going into it?

Thanks,
Scott

 

[BarryBecker]

Scott..I just read your questions.....I am having the same problems....did you find out the cause?
Thanks,
Barry