hmm..now i'm thinking about getting the 034 high flow cat. i'm just using the APR stage 1 so if i bolt on the high flow cat will the ECU adjust for the lower exhaust backpressure to increase the inflow of air and hence more power?

 

That's my understanding. I believe the Stage 2 flash is just to eliminate the CEL that will show up from the oxygen sensor.

 

Stage 2 has a different tune to maximize the higher flow. You will not get the full effect without it and you will have the pesky CEL. Stage 2 is free from APR, you may have a shop fee where you go though.

 

LOL. two different answers from respectable and knowledgeable folks.

 

Call APR. I can assure you on this. The fuel mixture is different.

 

I too am under the understanding that Stage II is for the CEL clear and II+ increases due to more fuel flow.

 

That is not accurate. You can contact Arin at APR if you need proof. It adjusts the tune for the higher flowing exhaust.

 

Got the APR stage 1 chip today. i actually stalled as i was pulling out of the parking lot...noticed the pick up instantly. 1st gear grabbed harder than ever - which was awesome. acceleration was great - a lot quicker. I sat in a lot of bumper to bumper traffic on the way home so i havent had a chance to really get on it, but its definitely a great upgrade and well worth the money. i will probably go to the HFC and Stage 2 in the next month or two.

 

Lotsa good info in this thread.
I had my 2000 tuned with apr stage 1 a couple months ago and after leaving the shop I had 2 cylinders mis-firing. I called apr and they told me the
problem was that I still had original coil packs with 130,000km on them they were probably failing due to the increased boost. The shop was easy to deal with and they reflashed the ecu back to factory settings and refunded me the full amount. I bought 4 new oem coil packs from ecstuning.com for $112 and installed them in my driveway in about 20 minutes. I've noticed a difference in responsiveness since then.
I'm wanting to go back and get the stage 1 flash again but I've been told it's better to do the DV before or at least at the same time.
I was looking into a test pipe too but I'm afraid it'll give me a CEL problem. Anybody know if a test pipe will give me CEL doing this? If so is it easy to just clear the code with a vag-com?
Also is it a good idea to get the stage 1 tuning if I have a, what appears to be minor, oil leak? I think the oil on the engine is coming from the head gasket and there's a little near the oil filter seal. Not alot of oil under there but is the added boost and compression gonna cause something catastrophic?
And there were some comments in this thread about gas mileage and I'm hoping that doing this flash will help with that. I currently get about 400km to a tank (all city driving). I have a pretty heavy foot but is that normal?
Sorry for all the questions but I'm thinkin there's alotta knowledge in the room.

 

If it's really a 2000, you may want to check out the other forums, as this is for the B7 (2005.5-2008). However, you can certainly go ahead and get the flash. Your DV may fail, but it's not a super terrible problem if it does. A test pipe will give you a CEL, and you would need to get the APR stage 2 program to remove it (which doesn't cost any more than stage 1). The PCV is a frequent point of failure on the B7, and can cause oil leaks as the crankcase becomes pressurized, that may be what's going on with your car in combination with some bad gaskets. Getting flashed shouldn't cause any catastrophic issues with the oil leaks, but it will probably accentuate them, so I'd get that checked out first.