P0171

[adial]

hi, has any one had a system running lean problem? as i understand it maybe a vacuum leak. has anyone else had this problem?

[cfc1]

Do you have any more info... does it say which bank it's refering to? (bank 1 sensor 1 for example)

You are right in thinking it could be a vacuum leak, as this can throw this code.. a dirty MAF (mas air flow) sensor can also cause it, try cleaning the maf and see if it sorts it. The MAF should be on your air box.

You could also have a dirty/faulty O2 sensor on whatever "bank" it is.. so get that checked too. Worh pointing out at this point that if it is one of these sensors that is faulty/dirty.. they can't be cleaned, you would need a new one, if that is the case buy from here

So... clean the MAF, then check for vac leaks if you still get no joy then replace the O2 sensor.

This could be worth a read too :)

[Andy36]

Do you have any more info... does it say which bank it's refering to? (bank 1 sensor 1 for example)

You are right in thinking it could be a vacuum leak, as this can throw this code.. a dirty MAF (mas air flow) sensor can also cause it, try cleaning the maf and see if it sorts it. The MAF should be on your air box.

You could also have a dirty/faulty O2 sensor on whatever "bank" it is.. so get that checked too. Worh pointing out at this point that if it is one of these sensors that is faulty/dirty.. they can't be cleaned, you would need a new one, if that is the case buy from here

So... clean the MAF, then check for vac leaks if you still get no joy then replace the O2 sensor.

This could be worth a read too :)

Accordiing to the toyota manual,it could be one of these. Air hose( hose looes),fuel line pressure,injector blockage,oxygen sensor malfunction(bank 1) ,air flow meter or water temperature sensor. The water temp could be your problem,their tends to go sooner than the other sensors.