Hitman47

All,

I have read up on a bunch of people that had this issue before. But, I'm not sold on what the fix actually is, still. Only thing I've done, so far, is replaced the MAF sensor.

Car:

• 2003 2.7T manual

Symptoms: (yes, car is NOT being driven until this is resolved)

• Tach revs sporadically from 0-2500
• Engine shakes
• Car bucks as if a new driver is tryin to drive a manual
• Poor acceleration; floor the pedal and it just crawls
• Engine stalls, battery light comes on
• ESP light on
• ** Ignition turns over just fine, btw & no distinct smells anywhere

Codes:

• P0431 - Warm Up Catalyst Efficiency Below Threshold (Bank 2)
• P0491 - Secondary Air Injection System (Bank 1)
• P0492 - Secondary Air Injection System Insufficient Flow (Bank 2)
• P0421 - Warm Up Catalyst Efficiency Below Threshold (Bank 1)
• P0442 - Evaporative Emission System Leak Detected (small leak)
• P0102 - Mass or Volume Air Flow Circuit Low Input
• P0172 - System Too Rich (Bank 1)
• P0175 - System Too Rich (Bank 2)

NOTE: Ignore the MAF related code as that was pulled before replacing MAF sensor. Also, ignore the SAI related codes as I have the SAI delete plates on the way and official VCDS/Vag-com en route, too, to code the SAI out.

So, given the rest of the codes and the symptoms, what are the gut reaction thoughts? Would a catalytic converter failure/leak trigger all this? Of course, Vag-com will give a lot of insight once it arrives. But, while my car is just sitting here, in the meantime, want to get some experienced feedback before I start pulling more parts.

Thanks, all! Happy to add clarification/more info to anything.

Studenta6

Do a smoke test and a boost leak test, then fix your vacuum/boost leaks.

Hitman47

Yep, doing that. Will post the results after.

dwengi

You stated EPS light is on. Do you mean ESP?

If rather it is the EPC light you will be in limp mode with significant loss of power and zero throttle response.

Hitman47

Yeah, quick typo. ESP light. Post adjusted

johnkk

You might get lucky and only have a vacuum or boost leak, but you should also check your cats for clogging. My 2.7 usually misses under full boost conditions when there are boost or vacuum leaks, but idle and low boost is OK. Only time it behaved like yours was with bad MAF. Since your MAF is new, thinking cats. I had similar issues with a 4.2 Touareg engine when one of the cats was clogged.

Hitman47

Got the SAI removed, found a couple torn hoses and replaced.

Now, ready to take out the EGRs and block them off (block off kit already in-hand) & then code out the SAI fully.

Question, though... any experienced advice (walkthrough, DIY, etc) on how to access the screws for *these? (the 5 of the holes outlined in this picture) Thanks, all!



*These are a reference picture, only; mine are still fully attached to the car.