I just bought a 1999 Audi A4 1.8T Quattro.
It has 120k miles on it.

..and now it has a few issues.

I have 3 engine codes that came up today:

1. P0018 (engine coolant temp (ECT) circuit high)
2. P1128 (Long term fuel trim B1 system too lean)
3. P1136 (Long term fuel trim add. Fuel B1 system too lean)

I am curious if these are simple fixes, or if it's going to cost me.

4. Also, my airbag light is on, and the car has never been in a wreck, and the airbags have never deployed.

5. The ABS light is on, and the brake light is flashing.
The brakes are working just fine as of now, and the guy I bought it from said it was just a sensor.

6. Another issue that I have, is that when the turbo spools down, there is a kind of light rattle from the engine.
Someone installed a boost gauge (very poor job) and it is only reading up to 4psi while driving? Is that way off? Possibly installed wrong?

7. The final thing is while driving 40mph +, I hear A LOT of road noise, only which seems to be coming from the passenger front side of the car. It goes away around 50mph, but comes back at 70-80, and goes away over that. I've read that the tires could be the cause, or possibly bad bearings. How can I tell?


Thanks for any help, I really appreciate it, and hope to enjoy the new car.
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1999 A4
1.8T Quattro