VW Jetta

I bought a VW 1.8L t jetta 2001 ran all summer and now doesnt seem to want to be running at all. I have started by replacing the spark plugs due to my belief of the car misfiring and noticed that ir was running to rich. The plugs came out black and i looked at the computer codes and it is reading
P1545 TPS
P1432 Secondary air injection valve open
P0102 mass or volume air flow circuit low input

I have taken it to a mechanic and he cant figure out what the problem is.

The previous owner has replaced everything under the hood and upgraded to the next level.

Those codes are relatively easy to solve.

If your "mechanic" can't figure out the problem(s), take your vehicle to a competent tech who is familiar with VWs.

A lot of it has to do with the computer he said cause everything is upgraded its not factory so im trying to find someone who knows a lot about building and running aftermarket turbo cars!

So is modded... Good luck with that.

You could take it to the person that did the mod in the first place.

The thing is, when you mess with today's cars they are tweaked from factory to a tight setting. If you disturb one thing, other issues will follow. The person that did the mod should done the homework right in order to make it run right. When comes to high performance, do not expect the vehicle to run as factory settings. These engines are really pushed from factory to get the most out of them with a blend of Comfort, Economy, Power and Driveability with the minimum amount of maintenance.

Once a parameter has been changed the whole setup changes. Just bolting on a Turbo is not like changing plugs or replacing an air filter. The induction system needs to change, the exhaust needs to change, the tranny (if automatic) needs to change (shift points, strength, etc...) and so on.

Even if the computer was replaced, it has a different mapping. I you put the car on a Dyno, you will find out the HP/Ft-Lb is not that much after all the headaches and "wallet" aches.

Now you are chasing your tail trying to figure out what is wrong. Is not about been pessimistic, just realistic.

Thanks for the input. I know that once you change one thing everything else has to change. I bought the car off the bank so I dont know who originally upgraded all the modes. I have a friend looking into it for me right now. I know it sucks im trying to be positive about it but cash is tight right now so im just waiting till I get some more cash flow to do anything at the moment thanks so much for your input!