Car is acting terribad. Help!

[19984V]

First I noticed my idle was stuck at 1900 and it popped a code "lean bank 2"

So i replaced the PCV and the IAC valve.
Car seems better for a bit but it just just popped the same "lean bank 2" code as well as misfire cylinder 6 AND the idle is screwed up again. Its very inconsistent. To make matters worse my gas mileage has been shot to hell.

PLEASE give me some ideas!!!

 

[Wynn]

Start by looking for vaccuum leaks. A leak anywhere past the throttle body could cause a high idle.

 

[19984V]

would that cause a misfire and a lean bank 2?

 

[Wynn]

Im not sure, but if air is getting into the combustion chamber that wasnt metered by the MAF, then the computer wouldn't know it's supposed to add more fuel. Start the car then take a can of carb cleaner and spray it around the base of the upper intake, then the hoses and accessories on the intake, and lastly around the lower intake. If the idle changes when you soray a particular spot, you'll know you have a leak there.

 

[MLS]

Do not spray carb cleaner on the painted parts it destroys paint! (intake and valve covers)

 

[DVJ38]

Well it could be a lean misfire on that cylinder. May want to check fuel pressure and ohm out the injectors. Check all the plugs, replace if fouled since a set of autolites are so damn cheap. Deffinently check for a vac leak though.

 

[RIO RED SNAKE]

^ try the plugs for sure first, if not you may need new wires for that misfire issue...my car did that a while back, new plugs and wires solved it, as for the high idle try the TPS sensor..it might of went bad too

 

[Wynn]

+1 on the tps too. Mine cracked once and caused a high idle.

 

[Njc0las]

Could it not be a bad o2 sensor as well?

 

[RIO RED SNAKE]

^no

 

[DVJ38]

^no

Thanks for the explaination. :loser:

A bad oxygen sensor wouldn't cause a misfire, it would most likely just throw a code for a bad oxygen sensor or give a faulty reading of rich or lean.

I think it could be a few different circumstances. You may have a lean misfire (too much air or not enough fuel) causing both the misfire code and the oxygen sensor code. If the engine sees a misfire it may raise the idle, but I think you are probably getting too much air somehow and that is what is causing the idle to be high.

You may have too much air getting in somehow (vac leak) causing the idle to be too high and causing the lean code, while you have a bad set of plugs or wires causing the misfire.

So replace the plugs and replace the wires if they're a bit old, then check for intake and exhaust leaks.

BTW, if the IAC was bad it probably would have set codes for lean bank 1 and lean bank 2.

 

[Tx_Diablous]

I have had misfire codes three differant times. Two were fixed with injectors and the third with a new set of plug wires. If your computer is in learn mode your gas mileage will suck a bit. BTW I am guessing the hanging idle is not related to the lean code. If you can data log look at the MAF signal when the idle is high and compare it to when the idle is normal. If it goes up with a higher idle then the leak is through the TB. If it is the same high and low then it is something like TPS, IAC, or a vac leak.

 

[Njc0las]

^no

Thanks for the explaination. :loser:

A bad oxygen sensor wouldn't cause a misfire, it would most likely just throw a code for a bad oxygen sensor or give a faulty reading of rich or lean.

I think it could be a few different circumstances. You may have a lean misfire (too much air or not enough fuel) causing both the misfire code and the oxygen sensor code. If the engine sees a misfire it may raise the idle, but I think you are probably getting too much air somehow and that is what is causing the idle to be high.

You may have too much air getting in somehow (vac leak) causing the idle to be too high and causing the lean code, while you have a bad set of plugs or wires causing the misfire.

So replace the plugs and replace the wires if they're a bit old, then check for intake and exhaust leaks.

BTW, if the IAC was bad it probably would have set codes for lean bank 1 and lean bank 2.

Whoops, I somehow missed the misfire part.

 

[sean m]

did you figure this stuff out yet?