 1995 Mustang GT Engine problem
Hi, I'm Maciek from Poland. I just bought 1995 Mustang GT and I've got few problems which I can't get rid of. I've tried searching for answers but it's just too many ideas to fix the problem or problems. You guys are expirienced so maybe you can put everything together and come up with some one good solution or just a few. It's almost winter in my country so it's hard to work on the car.
here it is: that's what the guy that sold the car said: it's 305 horsepower at the dyno. I doubt that. The car looks basically stock only things that I can notice is Full BBK exhaust (headers are stock I think) and huge K&N cone filter inside the engine bay (sucks warm air) MAF looks also stock.
I've got those codes:
552 - (O) AIRB solenoid/circuit failure - Solenoids (smog pump deleted so probably thats why)
311 - (R) AIR system not working - Single, Right or Rear HO2S - Air Injection
314 - (R) AIR inoperative, Left or Front HO2S - Air Injection
181 - (M) Fuel system was lean at part throttle Single, Right or Rear HO2S - Fuel control
181 - sometimes during driving it comes up (check engine light) for a few seconds only, but not always
As for performence: it has not less than 7 sec to 60 MPH, so 200 horses at the most, not even as fast as the stock one
engine has problems with idle, it's low 600-800. If it's cold it's ok or surging. If its warm it's surging and finally dies
at low rpm feels like engine is starving for fuel or air, have push a bit more gas to start rolling, then could choke for a second, but only on low rpm
I've cleaned MAF, checked for leaks, everything looks fine.
2 things: while driving at low rpm I can hear something like "tiking" from the engine bay. I think it's exhaust leak, before O2 sensor, passenger side, wiled guess, if the car is stopped with engine running I can not hear that. Seems that I can hear that when load is put on the engine only at low rpm.
Also my fuel pump makes strange noises and it's loud. First I thought that replacing it will fix all problems but lately the car backfired so it got me all confused (still old fuel pump). Happend only one time
AT high rpm seems fine but I think is slow | 
