View Full Version : more CEL codes

11-06-2007, 12:31 PM
ok, so i took a friends 98 A4 1.8T 5spd to get it scanned becasue its not boosting more than 4-5 psi. he has APR chip, full 2.5 exhaust, and cone intake filter. and ebay FMIC.

the codes are:

P1128- sys to lean
P0133- Bank sens 1 too slow
P1602- power supply voltage to low

the last code is that h never tighten up the battery terminal after having it disconnected.

second code is it the pre- or the post- cat o2 senosor?

and the first code..could it be that the MAF is reading too low, maybe dirty, or bad?

Fier Ringe
11-07-2007, 02:58 PM
P1128- You need to look for a vacuum/boost leak. If you are only at 4-5psi you probably have a leak somewhere. If there is no leak then your MAF is toast due to the oil on you cone air filter.

P0133-Bank 1 Sensor 1 Oxygen sensor has aged and is not reacting as quickly as it should. It needs to be replaced. It is the front, or pre-catalyst oxygen sensor.

For any performance or OEM parts call Brain at Avalon 303-400-3001 or checkout their website: www.avalonmotorsports.com

11-12-2007, 08:49 AM