Check engine light still on after 3 repairs

toyota
rav4

#1

97 Rav4. Check engine light has been on for over a year. I’ve taken it in 3 times for repairs: 1/EGR solenoid valve replaced; 2/ EGR vacuum transducer and valve replaced; and 3/ MAP sensor replaced. After each repair the engine light came back on after anywhere from 50 to 400 miles of driving.

While my mechanics are highly rated here for honesty, I’m beginning to wonder whether they are actually doing the work specified (since the engine light will stay off for a while anyway, just by having it “reset”). To give them credit, they did tell me when doing #1 above that that might not solve the problem, and I might need #2 done. But after #3, the prob was supposed to be solved and it isn’t. Why is it that difficult for them to find out what’s causing the check engine light to be on? Should I trust them?


#2

I don’t remember what level of sophistication the 1997 cars had, but I suspect they are new enough to have the error codes like [P1234] Take your car to an auto parts store that will read codes for free and get the code, not the English description and post it back here.

It wold appear your mechanic is replacing parts and not doing the testing that is needed to determine what needs to be adjusted or repaired.


#3

with the age of your car, and the way all the parts (sensors) are designed for about the same term of service, I suspect that one after another are indeed failing. That is why they originally advised you to replace two sensors. they knew that the second was about to fail because the first had failed. But do get the codes, and post them here because these pros here can really help you nail it down, and even advise you as to what is going to fail next.