Quattro 88 80

I just got the car (2002 ar with 96kmiles) a few weeks ago and I can't get it inspected because of the CEL.

The codes I'm pulling are

16815 - Warm Up Catalyst; Bank 2: Efficiency Below Threshold
P0431 - 35-10 - - - Intermittent
17536 - Fuel Trim; Bank 1 (Mult): System too Lean
P1128 - 35-00 - -
17538 - Fuel Trim; Bank 2 (Mult): System too Lean

I don't have a Bentley yet so any troubleshooting advice would be great. (Someone selling a Bentley with that advice would be even better.)

I do a full reset of the codes and they come back on the first "hot start" condition.

dcsat

I'm no expert, but it looks to me that either the O2 sensors are bad, or they are good, and the CAT is bad. I'd lean more toward the Catalytic.

If the post Cat O2 sensor is showing rich it seems likely that it would try to lean the mixture. Well the Cat isn't doing its job, and now you are running too lean.

Anyone else?

Quattro 88 80

If I run a readiness test the (4) O2 sensors pass. Reading Measuring blocks 46 & 47 I get widely varying results. Both heat to 605C running on the highway at 75mph for about 10 min, however B1 reads .62 (i assume volts) and B2 reads .88. In addition to that the third field in those measuring blocks reads B1 - PASS B2 - Fail.

Can anyone second that this is a bad B2 cat for sure? Is B2 the driver's side?

My indy thinks so and I have a bad feeling he's right.

Do I go for an OEM replacement or piggies?

Pete@ECSTuning

B2 is the driver's side. If the 02 sensors pass the readiness test and the voltage varies that drastically it would seem that the cats are the problem.

Piggies/OEM - that debate is up to you

Quattro 88 80

Chris,

Thanks for the info. What do you guys offer in the way of cat replacement?

Does anyone here have a several thousand miles on a VAST setup? How are things holding up?

Pete@ECSTuning

Sorry for the delayed reply, I'm not in the office on weekends.

For cats we have universal replacements varying in whatever diameter of your choosing. Basically one of these and a couple of exhaust clamps or a trip to the muffler shop will get you on your way.

Click here for our cat selection

Quattro 88 80

I appreciate the info.

Adrian02S4

In all the posts about P1130 and related codes... no one seems to post
if it was vacuume leak or MAF or other. That would be helpful to close the loop on making searching the forums useful.