QuestionThe check engine light has been on for two weeks but still runs absolutely fine. Not a gas cap issue. Engine light came on at 51 mph with a 32% lien (whatever that means).
Took it to a local mechanic who says it either needs a tune up ($300) or an emission test ($160) to determine the problem. They think extra air is being drawn in from some outside source.
I saw your post on 6.2.2004 on the same code. Any thoughts?
Aside from that, what's a typical charge for changing the timing belt in a 99 4Runner?
AnswerYou did not tell me the mileage on the odometer but it may not be relevant anyway but it would help.
In any case the DTC PO171 indicates a lean condition, this is caused by the air flow meter located just behind the air filter on the intake tube, your local mechanic is wrong, here is how to fix this trouble code:
Remove the air flow meter and clean the very small platinum wires inside the housing of the af meter with an electronic circuit cleaner, it is important not to use anything else, you can get it any radio shack or electronics store, just spray it into the opening to clean the accumulated gunk off the wires, clear the DTC and you will be good to go, install a new air filter.
The timing belt should be replaced at 90,000 miles and a normal cost should be around $300 max.
