Have you looked at the precat O2 sensors? Reading this forum, those sensors appear to start failing with lousy mpg as the only clue, no CEL. If you got a Scanner that can pull live data, it may show your fuel trims starting get out of range as a more scientific method of investigation. Sorry, not an answer to your question directly in regards to the MAF
i bet the answer is connected with the topic direct!
What could I add, at the moment i have exchanged O2 sensors, all 4 to SMP SG450 model (universal oxygen sensor, on ebay ~20$/pc). Vehicle works the same, i do not have at the moment update on consumption rate, but i will have soon.
long/short are -5%~+5% range, so good. Old ones was at the same range, no CEL with old ones. I'll test new ones and reply about consumption.
I use scantool under linux, so if someone likes to share/compare own livedata with others, i would appreciate it
why I have started that investigation about consumption, couse I had about 16-18mpg on highway about half year ago, and it suddenly dropped after vehicle was parked for a month.
What is done with vehicle:
changed intake gaskets
changed o2 sensors x4 (today)
cutted out CATs
changed spark plugs
changed wires on spark plugs
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tyres are standard demension 31-32" on 16 stock rims
I made suspension lift with torsion keys 2-3" front+rear
Seems like nothing more to add.
Thinking more about vacuum leak, but do not have smoke machine to check it, by long/short terms seems no vacuum leaks appear (if there is, long trim should be +20 at my memory..) am i correct? if short/long good - then no vacuum leak should be
UPDATE...
Short term ~ -2~2%
Long term on one side +10 other +14%... ? what could it be..
Generally no powerloss, engine pulls good; What doest mean that long term? leaking petrol injector or leaking seals somewhere on intake manifold? whats' the best way to find out?
