jayk_S4

car has been acting up recently, so i decided to purchase a vag com from ross-tech and see if i could figure it out before taking it to a dealer again. any opinions on the following vag results? first vag i've ever pulled but looks to be obviously the driver side o2 sensor before the cat, but would that cause the misfires? thanks

Address 01: Engine

Controller: 8D0 907 551 A

Component: 2.7l V6/5VT G 0002

Coding: 06611

Shop #: WSC 06325

7 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected

P0300 - 35-00 - -

16688 - Cylinder 4: Misfire Detected

P0304 - 35-00 - -

16685 - Cylinder 1: Misfire Detected

P0301 - 35-00 - -

17539 - Oxygen (Lambda) Sensor; B2 S1: Internal Resistance too High

P1131 - 35-10 - - - Intermittent

16534 - Oxygen (Lambda) Sensor B2 S1: Malfunction in Circuit

P0150 - 35-10 - - - Intermittent

16689 - Cylinder 5: Misfire Detected

P0305 - 35-10 - - - Intermittent

18010 - Power Supply Terminal 30: Voltage too Low

P1602 - 35-10 - - - Intermittent

Readiness: 0010 0001

reefer_bob

Any service lately?

jayk_S4

Its a 2000 s4 with 81k miles, never chipped (as far as i know) and never modded. I had it at the dealer for 80k mile service, it ran fine for about 1200 miles than started misfiring and the check engine light came on. took it back to the dealer who told me it was my diverter valves, i replaced them, and it still has the same symptoms. not wanting to be misled by the dealer again i decided to vag it myself.

E Vader

...you might want to look at putting new plugs in. Also, I have found good results with raising the idle 20-40rpm on lemmiwinks to address the S4 missfire issue. S4s missfire off the lot new so it is just a matter of maintaning a tolerable amount...IMO.

jayk_S4

already tried replacing the plugs, no difference. the car drove perfectly with no misfires (that i could feel) until just a couple weeks ago, now there is a noticeably rough idle and it has trouble accelerating.

E Vader

Do you have lemmiwinks?

sj6sp

Inspect connections and replace if you don't find anything.

jayk_S4

Nope, do you mean to adjust the idle?

sj6sp

If their is a significant difference between left and right side idle and part throttle trims, that would be more evidence the O2 sensor is the cause.

jayk_S4

Is the o2 sensor visible from above? Just took a look where I thought it should be based on a diagram, but it looks like there are heat shields in the way?