P0491 and P0492 Codes

Bimmer Ese · #1 02-04-2008, 09:44 AM

Well, I have the infamous P0491 and P0492 codes. I've already replaced the valve (the one that's on the passenger front side of the engine). The old one was pretty toast. The light was off for about a week. Now, it's back on. I can hear the secondary air pump come on when I start it up in the mornings (faint sound). Could it be the air pump? All the hoses appear to be in good shape.

Any help would be greatly appreciated.

Dan

jst2878 · #2 02-05-2008, 10:37 AM

insufficient flow in bank 1 and 2. if you need to change two parts and you only changed one then i suggest you change the other.

Bimmer Ese · #3 02-05-2008, 05:32 PM

Quote:

Originally Posted by jst2878

insufficient flow in bank 1 and 2. if you need to change two parts and you only changed one then i suggest you change the other.

Picked up the air pump this afternoon. $287 with tax...ouch!!! I'll tackle it this weekend.

Dan

Bimmer Ese · #4 02-26-2008, 01:43 PM

Well, I didn't tackle it that weekend, so I tackled it last night after school. The light was off for a couple of weeks until yesterday. Looks like it was the pump. You could hear the motor in the old pump come on and off. With the new one, you cannot hear anything. Hopefully, this will solve my problem.

Dan

yenanx5 · #5 06-17-2009, 08:20 PM

Quote:

Originally Posted by Bimmer Ese

Well, I didn't tackle it that weekend, so I tackled it last night after school. The light was off for a couple of weeks until yesterday. Looks like it was the pump. You could hear the motor in the old pump come on and off. With the new one, you cannot hear anything. Hopefully, this will solve my problem.

Dan

Dear Bimmer Ese,
I also has the same problem. I did replace the #8 (second air valve) and #7 (the hose to the air pump). I am thinking buying the air pump.
In your thread, you replaced the pump, was it solve your problem?
Please advice.
Thankyou

Bimmer Ese · #6 06-17-2009, 11:52 PM

Yes, the pump fixed the problem. Haven't had any problems thus far.

Dan

tonycajjo · #7 04-27-2008, 02:09 PM

Quote:

Originally Posted by jst2878

insufficient flow in bank 1 and 2. if you need to change two parts and you only changed one then i suggest you change the other.

what parts would those be? just the two hoses?

Bimmer Ese · #8 04-27-2008, 07:32 PM

The two parts are the secondary air pump (number 1 in the picture below) and the valve (number 8) that is located towards the front of the engine. When I removed the valve, it was full of condensation.

Dan

tonycajjo · #9 04-28-2008, 01:43 PM

first off let me say thanks for the response. Thank you!

i couldn't seem to find the part numbers for them on realoem.com

i looked in all HVAC catagories, i have a 4.4i, is it possible that my setup is different from what you described above?

either way im going to take a look around and see if i can find whats pictured above, check the hoses and see if that valve it fouled. i reset the alarm and it hasn't come back on but i dont want to cause more unnecessary damamge by ignoring the problem.

tonycajjo · #10 04-30-2008, 02:57 PM

there was a black hose with a blue strip comming off that valve and it was all cracked up at the end. i trimmed about 1/2 inch off and reattached it. im going to clear the codes later on and see if it they dont come back.

i'm hoping that was the problem. it may be time to sell this one and get a newer one with CPO. anyone want a 2002 X5 with a working engine light. haha. seriously though, i love this truck.