This is very interesting. I myself have a 2001 TT 180 FWD and I'm experiencing a very similiar problem. I'm running an APR chip, K&N cold air intake, Race N-70, Forge 007, and Borla Exhaust. At first I thought it had to do with the spring (green) in the Forge 007 not being stiff enough, so I switched to the yellow spring and found some improvement.

I just wasn't happy though and did some research and was told by the folks at ECS Tuning that I needed to upgrade my injectors to the 225 HP version because it appeared to them that the car was running too lean. Well I installed the new 225 HP fuel injectors and now I'm really having a helluva time with misfiring. ECS is telling me to switch to a colder spark plug, but I'm not convinced that this is causing the misfires in the mid RPM ranges that really drag the car down.

I'm not interested in going to the dealer because they are totally clueless when it comes to mods. Does anyone know of a good performance tuning shop in the Naples/Ft. Myers FL area that can troubleshoot and fix this problem. I think that I'm at my technical limit and I'm not afaid to say that either.

Thanks

 

Well, here is the outcome to what almost drove me into grabbing a sledgehammer and redesign my TT. The misfire was nothing but a bad connection on injector # 4. I replaced all the coils, plugs and the air mass sensor thinking that could be the problem but once again it was just a poor connection on injector # 4 which my father discovered yesterday morning while trying to figure out why I wasn’t getting gas. The gas problem was not the pump or the ECU, it was just a blown fuse, number 10 to be precise. It has something to do with timing. I am sooooooooo happy words cannot explain.

TTTONYD here is what I would do:

1. Check that the timing marks on the cam and cranck pulley are where they are supposed to be
2. Check the car's ECU for codes to aisolate the problem
3. Didn't say how many miles on the TT but if is close to tune up time, replace plugs and interchange coils to see if the problems gets worse.
4. Check all fuses
5. And eyeball the engine looking for loose vacum hoses

When you do all this let us know what you came up with......Also wanted to say thank you to those that participated and helped me with my problem

 

I really like what you're saying and it makes a lot of sense. It does appear that most of my troubles occured once I installed the new fuel injectors so perhaps it is an electrical issue. Tell me something though, did you get any Check Engine lights because I sure didn't.

 

did you fit the earth/ground strap when fitting new injectors "if it has one" I did this and took a few hours to solve the problem I now use noid lights to ensure the injectors are getting power.

http://images.google.co.uk/imgres?im...l%3Den%26lr%3D

 

TTTONYD Im from the Ft Myers area and know a bunch of technical mechanics that work at VW and Audi that could probibly assist you in fixing issues. PM me with your info and maybe we can start up a TT club in the local area to help with each others issues or mods.