UK Car Repair Questions? Ask a Mechanic for Answers ASAP
I persume by "air amounting messuring" you replaced the MAF (mass air flow meter) is it aftermarket or genuine?
Is the the only code set P0171?
Fuel pump replaced..so did you replace the fuel filter at the same time?
Yeah cause low fuel pressure can cause that code to flag up..so if fuel pressure is normal and holding,the MAF is genuine.. you've ensured that you have not got any exhaust leaks especially before the upstream o2 sensor...have you had them check for vaccum and intake leaks..that normally has to be one things top of the list to be checking out..ideally i would advise the use of a smoke machine to fill the intake aswell as the vaccum system on the engine to help identify any leaks..if that hasnt been done yet..then id advise that being the next step...you could be looking at leak in one of these off setting the fuel tirm because it see extra unmetered air so the fuelling will increase to compensate for that..live data on scanner looking at LT fuel trim and O2 sensor live data would maybe show that..