41 and 91 KOER running lean
09-25-2010, 01:04 PM
#1
Thread Starter
Join Date: Sep 2010
Location: Ca
Posts: 6
41 and 91 KOER running lean
So Ive been told its bad 02 sensors but now I hear there are before and after cat 02s and I dont know which ones I need. Its running lean according to the codes and has very rough cold start up, I have to be on the gas or it will die. It pops and is just pretty rough running untill it gets warm but it goes about half way up the normal temp range which is higher then when I was first driving the car. Ive cleaned the IAC and MAF properly.
09-25-2010, 01:47 PM
#4
D.R. THE PATHETIC DORK
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
they are before and the fool at the parts store is just that = clueless, had he a clue he'd know that that car has only 2 and they are before cat as obd 1 does not have catalyst monitors which are done via post cat o2's......and fyi, I would not go throwing parts at it to solve a lean issue on both banks without verifying the prob, it's rare both o2's are bad at the same time, often when I see codes for 02's on both banks indicating a lean condition, I first look for vaccum leaks , tears in the rubber boots before the maf, if your car is SD look for vaccum leaks, fuel pressure issues, o2's are often not in play on cold start since the car runs in open loop operation until ect sees a certain temp then o2's are switched on and at that point control a/f, if your prob is on cold start then I'd look at such things as ect, act, carbon build up in TB or intake.cumbustion chamber track, or Fuel pressure issues, or a vaccum leak, ect ect.............
Furthermore, first thing I'd check would be the o2 ground wire at the back of the heads/ intake area = orange wire on an eyelet iirc
Furthermore, first thing I'd check would be the o2 ground wire at the back of the heads/ intake area = orange wire on an eyelet iirc
Last edited by mjr46; 09-25-2010 at 01:50 PM.
09-25-2010, 02:00 PM
#5
Thread Starter
Join Date: Sep 2010
Location: Ca
Posts: 6
they are before and the fool at the parts store is just that = clueless, had he a clue he'd know that that car has only 2 and they are before cat as obd 1 does not have catalyst monitors which are done via post cat o2's......and fyi, I would not go throwing parts at it to solve a lean issue on both banks without verifying the prob, it's rare both o2's are bad at the same time, often when I see codes for 02's on both banks indicating a lean condition, I first look for vaccum leaks , tears in the rubber boots before the maf, if your car is SD look for vaccum leaks, fuel pressure issues, o2's are often not in play on cold start since the car runs in open loop operation until ect sees a certain temp then o2's are switched on and at that point control a/f, if your prob is on cold start then I'd look at such things as ect, act, carbon build up in TB or intake.cumbustion chamber track, or Fuel pressure issues, or a vaccum leak, ect ect.............Furthermore, first thing I'd check would be the o2 ground wire at the back of the heads/ intake area = orange wire on an eyelet iirc
Furthermore, first thing I'd check would be the o2 ground wire at the back of the heads/ intake area = orange wire on an eyelet iirc
09-25-2010, 04:14 PM
#6
1st Gear Member
Join Date: Apr 2010
Location: Arizona
Posts: 54
i just had the same problem getting codes 41 and 91 making car run lean, it was a loom of wires rubbing against the oil pan near the front of engine, and shorted out two wires., fixed those wires and the problems were gone.
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