Throwing Too Lean code P0171

**!!!FAST!!!** · 09-05-2009, 04:55 AM

What should I check on this? 2000 T/A WS6. Just added BBK SSI Intake, 85 mm throttle body, SLP CAI, smooth bellows, lid, K&N air filter cleaned, Magna Flow cat back. While driving it popped the code. Also noticed that when warmed up and driving the rpms would not drop for a few seconds when I engaged the clutch or let off. If I let the tranny slow it down it would eventually hit a position that dragged the rpms to normal.

**SSTODD** · 09-08-2009, 07:36 AM

Is the MAF stock? If not put the stock one back in, or try cleaning the OEM one with MAF cleaner from any auto parts store. DO not touch or wipe the wire inside the MAF.

**!!!FAST!!!** · 09-08-2009, 03:07 PM

Originally Posted by SSTODD

Is the MAF stock? If not put the stock one back in, or try cleaning the OEM one with MAF cleaner from any auto parts store. DO not touch or wipe the wire inside the MAF.

It is stock. I have an SLP high flow MAF but I took that out and put the stock one back in. It looks pretty clean. But I did find out that the codes are saying both banks are running lean.

**35th-ANV-SS** · 09-08-2009, 03:18 PM

Originally Posted by !!!FAST!!!

It is stock. I have an SLP high flow MAF but I took that out and put the stock one back in. It looks pretty clean. But I did find out that the codes are saying both banks are running lean.

That SLP MAF has made your PCM think the car is running lean and is probably dumping a lot of extra fuel trying to compensate but never satisfies the condition.

You can also check to make sure that you did not scorch/melt your O2 sensor wires with the new intake/exhaust.

**!!!FAST!!!** · 09-09-2009, 05:36 AM

Originally Posted by 35th-ANV-SS

That SLP MAF has made your PCM think the car is running lean and is probably dumping a lot of extra fuel trying to compensate but never satisfies the condition.

You can also check to make sure that you did not scorch/melt your O2 sensor wires with the new intake/exhaust.

Wouldn't it throw o2 codes then. The wires look fine. Didn't change exhaust manifolds to cats just a catback system. I took the high flow off and put the stock one back on then disconnected my battery to let the computer recal for the stock MAF.

**DIRTY JERZY** · 09-09-2009, 05:42 AM

Clear codes with a scanner the same thing happened when I put my slp maf in it ran great at first then after a couple hundred miles it through the same bs codes I put the stocker back in and had the codes cleared have not had the problem since.

**35th-ANV-SS** · 09-09-2009, 05:48 AM

If you had your stock one stored for a while when you were running the SLP MAF, I would guess it is dirty.

Even if it looks clean, I would still buy some MAF cleaner and spray the hell out of it. The P0171 code is usually the MAF. It looks like SSTOD said the same thing.

I am not sure on this, but it may take a while for the PCM to relearn

with the new MAF.

You could also check for a vacuum leak downstream of the MAF. This would trigger the same code.