FYI codes 41 and 91

toms93lx · 09-27-2009, 11:29 PM

just want to know what you guys think......looked into everything for months and just so you know if you get codes 41 and 91 at the same time it is a electrical problem....most likely a ground.......not vacume leacks you get 42 and 92 if its vacum. bad grounds couse false readings. thats why if you are getting lean reading but running rich coused by bad ground either at the computer or the wire harness.

does this sound right to you guys too

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AdderMk2 · 09-27-2009, 11:40 PM

check the wire that goes to the back of your drivers cylinder head, from the O2 harness...

also, if you have had a bad ground for long enough, your O2 sensors are probably shot

TrimDrip · 09-27-2009, 11:52 PM

My car always showed 41 and 91 with a vacuum leak.

It could be a ground but, it also could be a vacuum leak.

41 and 91 are codes for voltage at the o2 senors is lean. it doesn't mean the car is running lean while you smell fuel out the pipes at idle.

toms93lx · 09-28-2009, 12:00 AM

if was vacume you would get other codes or just one of the codes either 41 or 91

TrimDrip · 09-28-2009, 12:03 AM

Quote:

Originally Posted by toms93lx

if was vacume you would get other codes or just one of the codes either 41 or 91

bull****, it means voltage to the senors is lean.

I have a 93 that gave those codes when I bought it. I fixed the leak and the codes were gone.

toms93lx · 09-28-2009, 12:11 AM

vacum leaks couse the true condition...i guess what i mean is if you get 41 and 91 and it smells like gas is getting poured out the exuast pipes its electrical. if you get 41 and 91 and dont smell gas its vacume

TrimDrip · 09-28-2009, 12:13 AM

Quote:

Originally Posted by toms93lx

vacum leaks couse rich fault codes or will pop other codes

a vacuum leak will pull in unmetered air that the MAF is not reading and cause your car to run lean. It will also cause there to be a heavy smell of fuel at idle and a rolling idle at times. A bad one will cause a really high idle.

toms93lx · 09-28-2009, 12:21 AM

i know what you mean but wouldnt that cause the o2s to try to compensate. if the were electriclly sound they should be reading rich not lean if to much gas is in the exaust

TrimDrip · 09-28-2009, 12:38 AM

That is why the car is rich because of them trying to compensate, the best I can figure. Once the sensors got the signal that the voltage is lean, it added more fuel. Sorta like a safe mode. Hell, you can run the car without the 02 sensors even plugged up. It will be rich but, it will run.

The car is not going to show a rich condition because of a vacuum leak because the car is running lean from the unmetered air the vacuum leak is pulling in. Make sense?