CEL on again

Hey all. New to the forum. Need some help. My 2000 Tacoma Prerunner 2.7 at 150k CEL popped on. Auto Zone said it was EGR valve. My husband put new one on then pulled hot post off to reset. CEL came on again. Took to Zone and same code. What else could it be? Thanks for any help. I love the forum. So much good advise.

 

whats the code

 

fyi, only like 8 or 9 possible codes actually say there something wrong with the part it referrers to. the other 100 some odd say the part is reporting bad tolerances for whatever it's supposed to monitor.

 

I had this issue in my '01. IIRC, it's a P0402, which is an EGR issue, as you said. Since you already went the most expensive route by putting in a new EGR valve, it should be an easy fix: the lines going to/from the valve may be clogged; pull those and run a wire through them to clear them. Clean the filter. It's right in front of the valve. Looks like this:



There's a filter in there (it twists open, IIRC)...take it out and clean it with compressed air.

 

P0402 They said.

 

yep, so this code doesn't distinctly state that there is an issue with the valve. it just says that theres too much air getting by the valve. so there should be a couple other parts to the EGR system. the actuator solenoid and a pressure sensor.

1, if the EGR is stuck open, it could cause this code.
2, if the actuator is faulty, it may not be closing the EGR all the way.
3, if the pressure sensor is clogged, it may be telling the computer to keep the EGR open longer than it should.

so there's at least 3 issues that can cause the code to come up. and im sure there are several others such as bad wiring. you really have to get in there and inspect all of these parts and test them mechanically and electronically to figure out the issue. otherwise youre just throwing money at it hoping it fixes itself.