cyclonebax

I have an 03 Audi A4 with about 117000 miles on it. The gas smell has happened 2 times in the last month. It almost fills the inside with raw fuel smell. Both times started after about 1 mile of town driving and continued for about 5 minutes.

I'm having difficulty finding where it is coming from. I would have thought with the amount of odor coming in the car, there would be a puddle under the car, but nothing.

I wiped my finger under the compression fitting for the fuel supply and it smelled like gas, but it was not wet. I went ahead and tightened it so will see if smell comes back.

I have heard that the injectors can crack and have an intermittent problems.

I also have the following codes(not sure if they are related):
17536 - Fuel trim; bank 1 (mult): system too lean
P1128 -001 - Upper limit Exceeded - Mil on
16805 - Warm up Catalyst; bank 1; Efficiency below threshold
P0421 - 001 upper limit exceeded - mil on

Any help would be appreciated

lyleswk

Codes are probably related becuase if you are loosing fuel the ECU is expecting to burn, you will have the lean running condition you describe. So you think it is coming from the engine bay? It could also be fuel injector o-rings. Have heard of those leaking.

cyclonebax

After tightening the compression fitting on the supply, the strong gas order has not come back.

However, the codes come back. This is consistent to reset and about the 3rd time I start the engine the codes are back.

Any ideas?

cyclonebax

After finding a vacuum leak, I got rid of code:

17536 - Fuel trim; bank 1 (mult): system too lean
P1128 -001 - Upper limit Exceeded - Mil on


Still have other code. Thinking of changing the downstream O2 sensor. Any thoughts?

lyleswk

First, how long have you driven it with the remaining code? Some codes take several drive cycles to clear by themselves. Not sure if this is one of them.

If it has been 5 or 10 drives at highway speeds and city speeds, then the Ross Tech website points to MAF and injectors also. I would start with the MAF simply due to ease and expense.

http://wiki.ross-tech.com/wiki/index...6/P1128/004392

cyclonebax

I have been clearing the code, but comes back in 3 start cycles. I will clean the MAF sensor first, per your comment. Then maybe get a new downstream oxygen sensor.

cyclonebax

Cleaned MAF sensor. Code stayed off for a few extra cycles (more than 3). Cleared codes, it came back again faster.

Is it possible to be the MAF if only bank 1 is setting code? If it was the MAF, wouldn't it set codes on both bank1 and bank2

lyleswk

Step back a sec. You said you had a strong gas smell. Do you still have that? If so, maybe you have a leaking o-ring on an injector. Not sure which one is bank 1, but look around the injectors for wetting and make sure it is not after a long drive where the block is very heated up. An idea would be to start the car first thing in the morning and let it idle for 5 or so minutes with the hood / bonnet up and cover off.

cyclonebax

Update.

Had a crack in a breather tube. Got new vent valve with breather tube and the additional breather tube that goes from manifold to bottom of vent tube. Difficult to change on a 3.0 l. Also changed all the vaccuum hoses in the area of the vent valve. Engine light has been off for 3 days. Longer than it usually stays off.

lyleswk

Glad to hear. I know this stuff sometimes just takes looking over the engine carefully which you obviously did.