ramiltor

Audi A4 quattro 1999 V6 2.8

I have this misfire a wile now. Car is shaking a little bit on low rpm, sometimes when driving highway check engine light blinking due to misfire.

Replaced cam chain tensioner and timing is good.
Replaced spark plugs.
Fuel pressure is by the book, new fuel pressure regulator works. Maf sensor is reading intake air temperature right.
Replaced catalytic converter on driver side just few days ago.
Replaced coolant temperature sensor.

One day stats having troubles start car when engine warm. It was coolant temperature sensor, but i noticed that: With bad Coolant sensor misfire codes disappeared and car works smooth, but was having problem to idle when warmed up. After replaced sensor car starts normal but 4,5,6 misfire came back.

Any idea what it might be.
Appreciate.

4Driver4

Misfires are the only codes you see? Nothing else?

ramiltor

With my chip scanner that is all i got

P300
P304
P305
P306

After replacing coolant temp sensor code for coolant disappeared.
After replacing cat. I had "oxygen sensor bank 2 low input" code (maybe because cleaned it with gas), but after 2 days disappeared also. Replaced cat, because did not pass emission test (cat efficiency) and i thought it was clogged, but it wasn't.

There is no more codes

4Driver4

Sorry, I don't look up codes.
What do they mean?

Do you have access to a VAG scanner?

ramiltor

P0300 - random misfire on multiple cylinders
P0304 - random misfire on 4
P0305 - random misfire on 5
P0306 - random misfire on 6

Not sure what is VAG scanner. I have regular OB2 scanner which you can read and clear DTC codes. I'm thinking to see audi/vw dealer to scan my car