Harddrive2000

Yes, I tried that already, VAG-COM ECU readings match the speedometer all the way. I have another suspicion on my mind. 85mph = 137kph which is the absolute highest she has gotten to (and that way after some serious pushing, at night on an empty highway). It could be that the limiter was set to 135kph instead of 135mph. In any event, a friend is sending me a replacement ECU from The States this week. Will test it out and see what happens. At least, then we can eliminate or validate the ECU issue.

Harddrive2000

Update folks. I got a replacement ECU with same part number and tried it out. Results were the same, could not exceed 83mph. No MIL, but i did get these 2 codes when i VAGed

16717
Knock sensor 2 (G66): Signal too high: P0333

17737
Knock control: Cylinder 5: Regulation limit exceeded: P1329

I already retorqued the knock sensor to spec so WTF!

turbo510

Pull plugs and see if you see any difference in plug 5; small beads on the insulator, etc. Also, run some high-octane gas and try again to see if there is a difference. You might try your local general aviation airport, the common fuel is 100LL, and see if the knock sensor code comes back.

Harddrive2000

No difference btw plug 5 and the others. Only one grade of gas sold over here, i have no idea what octane it is, but its what everyone uses

So i decided to do the seafoam and a compression test. Had to order the items from US seeing as they dont sell them here. Took three weeks to finally get to me hence my silence on the matter till now. Anyways, the seafoam arrived last week so i did the triple combo (crankcase, intake and fuel tank). Lots of smoke? yes, but not terribly high. Any effect on performance? I'll have to say nay. Compression tester Kit arrived today and i quickly went to work. Here are my results
Cyl 1: 215psi
Cly 2: 208
Cly 3: 215
Cly 4: 195
Cly 5: 196
Cly 6: 200

Unless i've misuderstood the theory of it all, i would say that these values look healthy?

I'm beginning to suspect that i may have a clogged exhaust system. Not the catalyst since they are out, but further back. gonna run a vacuum test next.

Harddrive2000

Update

So i had a chat with the guy who gutted both pairs of my cats. Apparently, after they gut the cats, they stuff some wire meshing in the cavity to create some sort of back pressure. Aha! i said, that mesh must be in pieces by now and was pushed into the muffler. So it goes like this:

1. My original cats got clogged and i had them gutted, they put the wire net in. Net gradually fell apart and was blown into the center muffler.
2. Later had the cats replaced (with used cats) when my tranny was changed. So now i'm on my second set of cats.
3. I instantly began feeling alot of heat in the footwell. Traced it to the cats, had them gutted cause i thought they were clogged (afterall, they were second hand), but in hindsight i now realize they were overheating because the center muffler was clogged by the wire mesh from the first gutted cats.
4. So now i'm on my second set of gutted cats with wire meshing inside.
5. Wire mesh begins to fall apart and ends up in the center muffler.

So i went to a VW/Audi breaker yard and they found me a used exhaust from cats to center muff. They swap out the cats, cut my center muff from the tailpipe muff and welded in the new center muff and i was back to stock. I looked into the old cats through the O2 sensor hole and lo one of them was empty, while the other still had the wire mesh in it, but it was already beginning to find its way up the pipe towards the muff.

The eshaust is flowing faster than before, i can tell when i place my palm in front of the tailpipes. Havnt had a chance to test the speed, but from normal driving around, she has a lot more torque (even with the AC on, she moves much quicker that she used to, and the kickdown is a lot better too). I think my problem is solved. Will update once i get a chance to do a full speed test.

BTW why am i using used cats? We dont have emission laws, so nobody sells new cats over here.