timjohnson

Hey guys, dunno if ANYONE can help !!! i keep getting bloody engine code fault 171 come up on my 2001 bugeye, which is engine running lean on Bank 1 . Usually associated with MAF and O2 sensors , both have been replaced with new ones. Ive got a Blitz power induction kit and after having a Baileys VTA dump valve on there went back to the original re-circulating one to see if it was that. The only thing i can put back to standard now is the air filter...but prob is someone decided to fit my alarm right in the place where the filter would go and now not enough room, but would having the induction kit on it keep giving the error fault. I wouldnt mind too much resetting it once inna while but its happening more and more often and bit worried that because its throwing up the error im getting a crap air/fuel mix ! and obviously dont wanna mess the car up. I only used to notice it on long runs before even with the Baileys dump valve on there, but now bit more often ! anyone help !!??? Cheers !
Oh yeh, ive also done an ECU reset few times so that it would forget previous faults.....

scoobiewrx555

Having a bailey VTA on there has other adverse effects, well done for getting rid of it and putting the original back on.

Your problem of running lean is down to your induction kit. The ECU needs a remap. The MAF sensor table needs to be rescaled to take into account your induction kit which probably has a bigger bore pipe than the original airbox. More air is going in but the ECU thinks there is the usual amount of air flow and therefore isn't fuelling sufficiently so you get a lean on bank one error.

Resetting the ECU all the time isn't going to sort your problem out, get it remapped.

timjohnson

yeh have heard of that before, but how easy or expensive is it to remap ? and how would i know wat to change with regards to the levels? one of my friends said those errors could be fuel filter, fuel regulator, fuel pump and then last injectors ? personally ive always thought filter as i know it can confuse ecu.

scoobiewrx555

Remap costs depend on where you go. Ecutek up to £650+vat, Open Source up to £400+vat.

If the car has never been mapped and generally runs ok apart from this error code you keep getting then unlikely it's your pump or injectors. I very much doubt your injectors are running out of fuel at your power levels and again if they were faulty you would get fuelling issues the whole time, equally if your pump was faulty you would get fuelling issues all the time too but it doesn't sound like it to me. If your filter was clogged likely your car wouldn't run well at all and and probably cut out on you now and again or all the time. If the fuel pressure reg was dodgy maybe you might get an issue with lean fuelling but that would normally affect the whole rev range and your car would be detting like mad therefore your ECU would be pulling timing and trying to add lots of fuel, and if that wasn't enough it would start to go into semi limp and eventually full limp mode if by then the engine hadn't gone pop. These parts i've just mentioned are generally very reliable and don't cause issue until you are at their limits, and at standard power you are nowhere near their limits.

I'm pretty sure your problem is induction kit related. Relocate your alarm, it's not difficult, and put your airbox back, or get the car remapped. Putting the airbox back and running a high flow flat panel air filter would be cheaper than a remap and it's just as good at your power levels and way beyond as any induction kit you like, and to be honest much more preferable.

dynamix

iTrader: (3)

Put the std airbox back on or remap with the induction kit (which is probably not giving you any extra power anyway)

timjohnson

hmm cheers guys, yeh ill look again at repositioning the alarm ! but thing is had the car 5yrs now, and only used 2 show up on long runs, so find it strange way its doing more often now ! and the cars runnin smooth as usual ....

Splitpin

You've been given the correct advice by two different people so the best option might just be to take it and see what happens.

There are a number of possible reasons why this problem might be getting worse - including damage to your MAF sensor, caused either directly by the induction kit or as a result of natural wear, making it under-read even worse.

The bottom line is that sitting there asking questions when you've got a rapidly recurring lean mixture warning is not something your engine is likely to thank you for. The car may feel "smooth" to you behind the wheel, but it it wasn't a problem, the ECU wouldn't be flashing the CEL at you. As has already been said, the induction kit is gaining you precisely squat (and probably losing you something). If you don't want to get it looked at professionally now, start by getting rid and seeing what that does to your CEL.