maf causing P0230? stage 2

[Arron]

Last day or two the cars been feeling 'sloppy' response wise. I'm thinking the maf is to blame as i usually get thru 1 every 9 month. Then last night it cut, each time in 3rd gear spirited driving

I know stage 2 does rely on the maf heavily for IQs so if its faulty would it also mess up the fuelling and cause the cutting?

Arron

[Poodle]

No, the map will have safeguards to avoid such occurences. Afaik P0230 can only be fuelling, wiring or ecu.

[Midnightclub]

Under WOT i thought the MAF didn't really do a massive amount... If it's cutting out under WOT i would've assumed an issue to do with rail pressure

[Arron]

Ah ofc.

Hmm! Think its time to bin the stock fuel filter housing!!

[Midnightclub]

If you can get it onto PP2K that should tell you for sure

[Poodle]

What makes you think its the filter housing thats the problem?

[Arron]

I've had a look today. One of the pipes at the bottom was unclipped on the filter housing. Pushed it back on

Because the design is wank. Prone to air getting in and the clips on the pipes are poor. The lid is common to let air in. I'm just gonna home brew some rubber fuel pipe t pieces and jubalee clips and run a inline universal diesel filter

[Poodle]

Are you sure you're not thinking of the XUD filters? The filter housings on these are pressurised at 3bar when running, they'd do well to draw air in. Never seen a problem with pipes randomly coming off either, have you tried cleaning up the fittings so the clips can move freely?

[Ruan]

If youre getting p0230 start looking at your HP pump or lift pump, I'll bet you thats the problem, many people have run stage 2 maps for years without a problem with the stock filter housing... Ill bet your lift pump, HP pump or regulator is dicky...

And its impossible to get air in the system, it's pressurised!!! Thats why they are pressurised!!!

[Dum-Dum]

As above. It wont be a maf issue, they run pretty much fine even with the MAF unplugged and on a S2 map alot of the time the MAF is useless as your flowing more air than it can measure so IQ is only set by the ECU on load (TPS) and revs and it guesses how much boost your likely to have.

If your feeling sluggish and cutting out its probable either LP pump, rail sensor or the regulator in the HP pump.


Take your fuel filter out and look for gold filings in the bottom and its a sign the LP pump is on the way out

[Arron]

Im suspecting lift pump, the regulator cant come out as the threads are ruined so id need a new HP pump, may be an excuse to upgrade

I pushed that pipe back on and its been fine. It was my mech that said its quite a weak design compared to other manufacturers i.e vag used sealed filters and spring type clips. The ends of the plastic pipes that connect to the clips go brittle and start moving. May be due to wear and tear but im sure i can homebrew better.

I know a lad whos HDi wont start with the stock fuel filter but runs fine with an inline filter. Im going to do it in a few week and see if it makes a difference, then change the lift pump

Chris i cant run without a maf so i cant unplug to dignose performance issues. It feels fine now at the moment, im sure that pipe been disconnected was causing the problem

[Poodle]

Yeah the vag filters are generally a much tidier design tbf, but then again i've never known a problem with our type of filter housing.

I reckon you might be right about that pipe.