youve all seen the ads on here ie: 25bhp or 20bhp tuning chip.
well its total rubbish and a con, all you get is a resistor that costs 27p per 100 thats right 27p per 100. what it does is connect onto the air temp pickup on the air intake and fool the ecu into thinking brrr its cold out there ill richen the mixture to help car along (think old days pulling the choke out) ok so the cars running and yes you may feel a bit more pull on a hot suumers day. so engine is purring away and the maf sensor and lambda sensor are talking to the ecu the lambda tells the ecu why you pumping so much extra petrol in as im sooty and hot, the ecu gets info from engine and its saying well im nice and hot as well, ecu instantly drops off the mixture to a point where as its sitting at its correct co2 level.
all the loadsa power u thought u had is gone you've wasted petrol and back to square one.
i tested one of these so called chips on a 2.0l galaxy
4% maf, 0.5 lambda, 975rpm tickover, air temp 17deg (it was actually 15deg.
4% maf, 0,9 lambda, 975 tickover air temp 3 degs. left it running for 5 mins and hey presto all readings went to normal.
moral of this is your being scammed and wasting your money i can backup all my testing with dyno runs, ecu readings short and long runs,
if you want more power buy a bigger engined car or buy a ecu reprogramme