97 HB 4wd 2.4l EGR ?'s

[benre]

I have a 97 HB 4wd 2.4l and my check engine light came on. Autozone read the code and it said
aaEGR- no/low flow detected
aa1- EGR passages blocked
aa2- EGR pintle stuck closed
aa3- EGR volume control valve open or shortened
aa4- EGR temperature sensor error

The guy at autozone said he thought it was the egr temp. sensor. I am not so sure.
I have done alot of basic tune-up stuff since i got the truck a little over a month ago. I changed the fuel filter, and an 02 sensor last week and cleared another check engine code. The truck runs decent, lacks a little power, and is getting only 16.5 mpg. Any assistance i greatly appreciated.

[seang]

I can't say off the bat if he is absolutely right or wrong.

Gears are low (4.6325:1), so 16.5mpg combined (hwy and city) seems about right. Are your vacuum lines cracked?

I feel that the EGR is important on our motors (I have the same exact drivetrain as you) because the engine is spinning pretty fast at highway speeds, and that can make alot of intake manifold vacuum. I disconnected my EGR for a while and my mpg went down to about 14, so I hooked it back up (some cars can do better without it I guess). I get about 14~15city/17~18hwy with EGR.

We have free downloadable factory service manuals so maybe you can diagnose something from it if you want to look around at it some.

[PEZi]

The EGR out is more of a performance thing.... don't expect better (or even the same) mileage when its removed...


with that said... sounds like the EGR isn't opening... the question is why?

cracked vac lines? bad valve?

[PEZi]

The EGR out is more of a performance thing.... don't expect better (or even the same) mileage when its removed...


with that said... sounds like the EGR isn't opening (or possibly stuck open)... the question is why?

cracked vac lines? bad valve?

[benre]

I haven't noticed and cracked vac. lines.

[jvillstangman]

check the vac line under the black round valve beside the egr is it broken or sucked shut. another thing to check is the ports in the intake if they clog it will make it run ruff.