[Biturbos4] Dang-nabbed CEL!!

Single Malt s_malt at yahoo.com
Thu Jun 21 13:43:49 EDT 2007

I have been having a great time with CEL issues of late.  I've finally gotten them all resolved and I thought I'd relate my experience.

I have a laser red 2001.5 6-speed sedan w/ 113k miles.

Over a year ago I participated in an Audi Club track event that may have contributed to a catalyst failure in the cats.  The logical thing to do was to upgrade the exhaust and thereby fix the CEL related to the cats.  Since that was lotsa dollars the car sat for the winter.  In the spring I replaced the dead battery (original equipment!) and hauled it into the shop for the exhaust.  While it was in there - timing belt (second time since I've owned it), water pump, timing chain tensioners, cam shaft seal, valve cover seals, and misc other things.  Cost? Don't ask.  This is why I bought a spare car (nice little '87 4kq) last year instead of fixing it last year!  

So the CEL for the cats went away and so began the saga of the *new* CEL - misfires!

I've been told many many times that these cars misfire on occassion normally.  It should *not* throw a hard code though.  Monitoring showed the misfires (100+ at a shot)  related to cylinders 1 and 2.  The misfires would happen on a lift of throttle or slow maintenance throttle while descending a grade.  Increasing throttle straightened it out and all cylinders fired cleanly even under full open throttle (my personal favorite).

Changed the plugs (it's been over 40k miles).  Slight improvement, but misfires still present.

Moved coil packs around, problem stayed with cylinder.  Replaced two coil packs (cyls. 1&2)  anyway - slight improvement again, but misfires still present.  Took it back to the shop.

They swapped POS's and problem stayed with cylinders.

They prescribed and applied a carbon blast treatment which as I understand is added to the oil and then the car is driven hard and then the oil is changed.

That did it.  No more misfires and the CEL is off and stays off!  Now I feel really really good about opening up the throttle and listening to that sweet sweet roar of the new ASP exhaust.  Not for everyone, but I freaking love it! :)

Time to re-install my chip now that things are operating so well!


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