I just bought a 99 4runner and the check engine light came on as soon as I took possession of it! I did some research here and before I bothered getting any code pulled, I removed and cleaned the MAF sensor. I replaced it and popped the efi fuse out and back in and now the check engine light is off. Is this typical?

 

yup. dirty maf will commonly blow the MIL at 50,000 miles and any time afterward

the intake design on the 4runner allows crankcase gasses to settle on the maf
when engine is turned off. this buildup is usually what needs to be cleaned off
for the maf to do it's job. it is inevitable. cleaning almost always does the trick
for another 30,000 miles. then clean again.

next time get the actual code. your o2 sensor and a/f sensor are going to
go bad soon (relative to miles driven, typically 110,000 to 140,000 miles),
so you want the actual codes next time that light pops to be sure of what it going on

 

Why not let the computer tell you what's wrong? That's the great thing about OBDII, your truck will tell you where to look.

BTW often the CEL works on 2 trip logic. One trip no CEL, 2 trips it comes on.

 

I don't have a code reader yet, and nobody rents them around here. Maybe a code reader would be a nice Christmas present. Why would the CEL or MIL wait for 2 things to fail?

 

Find an autozone store..They will pull codes for free for you..Make sure to write down the #'...ex.P0301,ect...And have them pull current and history/previous codes stored in memory..This will get you by w/o a scanner

 

Well not really two things, but one thing happening twice. I guess in case the first time was just a fluke.

 

ok, makes sense...
I'm in Canada ..no autozone here

 

Plus that way the used car salesmen can reset the ECU and you'll be off the lot and a few miles away before it comes back on.

 

Many autozones stopped pulling codes btw...