Hello. My car is an Alfa 156 2.0 TS 2001 and I have a few problems with it. First of all the errors: P1172, P1175, P1177 and P1178.
When I checked it for errors the message for all the errors (bank 1 or 2/low or high) was that the fuel mixture is not good. Those errors appear almost every 800-1000 km and I don't know why, because the flow meter is ok, the lambda sensors are working just fine and the timing was done by Alfa Romeo Service under my eyes (the mechanic showed me how he put the belts and everything by the signs). I've checked the lambda sensor to the local Alfa Romeo Service. The engine sounds ok and works ok.
Please, can some one tell me how can I fix this?
Is it possible that my flow meter to be broken without any simptoms?
A second thing is that I have a strange sound, like a short "crrrrr", somehow like when you want to change the gear without using the clutch and it comes from inside the engine. I can hear it between 2000-3500 rpm and mostly when I change the gear and go fast (2nd to 3rd and accelerating). You can hear it here YouTube - Zgomot ciudat la motor (Alfa Romeo 156 2.0 TS)
. Begin with 0:30 and you'll hear it soon.
The Alfa Romeo Service and another mechanic told me that this noise is from the "machine infeed", meaning it can't to the fuel mixture correctly and it makes that noise. My problem is that I think it's a mechanical problem caused by some part and I would like to know which is it. I don't know if "machine infeed" are the right words and I appologise for my english. I don't know it all