MAF or not MAF?

abmat

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Hi all,

Got an issue that’s bugging me.

Left for work this morning on my weekly commute. 160 mile drive. Stopped for fuel at the start, car was driving fine.

About 90 miles in, stop in traffic at a junction leaving the motorway. Go to pull away....nothing! Car has stalled!

Got it started, but it wouldn’t idle. Managed to hold some rpm and get it into gear and get moving. Had to stop again for lights and the same thing happened. Finally got it started and got onto the A34 where I pulled over straight away.

Luckily I had my laptop with me so did a scan and it threw up:

16468 - MAF/G70 signal too low.

Fault wouldn’t clear. Tried starting it a few times but it just cut out. Unplugged the MAF but had the same result. Plugged it back in, waited 15 mins, started and idled. Managed to do the last 70 miles to work with no issues, no rough running or further stalls.

Got to work and scanned again. Had the fault above plus:

16497- intake air temp sensor(G42) signal too high.

Finished work and drove the 15 miles to where I stay. Plugged it in and cleared the dtc’s. They didn’t return. Car drives fine, not low on power, no rough idle etc.

A couple of questions.

1. Are the MAF and air temp sensor part of the same unit?
2. Is this a sign that the MAF is on its way out, so should I just replace it? Or is it masking something else?
3. Is replacing a MAF just a matter of out with old, in with new?

I have had this happen once before, when my ecu was updated by djalix. Fault cleared and hasn’t been seen until now. We suspected the ecu had a moment and needed to adapt.

Sorry for the ramble. Any advice appreciated.
 
The G42 sensor isn’t part of the MAF, on my BKD engine it’s located on one of the hard plastic intercooler pipes which lead up to the inlet manifold, it’s held in place by 2 self tappers.
Replacing a MAF is dead easy , you don’t need to replace the whole thing (they often come complete with a big plastic housing that doesn’t wear out) , just 2 torx screws hold them in, but they are the security torx type so need a torx bit with a hole in the middle......easy enough to find though.
 
Cheers. As mine is a petrol from what I’ve read I think the MAF and G42 are part of the same unit.
 
Anyone know what measuring blocks I have to read for the MAF and what reading I should expect for a 3.2?