EGR issues. Need some help

[Yota4life]

haha good one. I bought a magnaflow cat for 1999 tacomas and put it on my 88 do you think that could be why my NOX reading was so high on smog?

[emsvitil]

No, I'd bet on the lack of backpressure...........

[Yota4life]

my CO% was almost ZERO so i must need a new o2 sensor and ill try plugging the exhaust some and go from there. but if the egr hasent been working the whole time that must be why i get horrible gas mileage. My 22re sucks gas like a big block

[emsvitil]

http://www.autoshop101.com/forms/h61.pdf

[Yota4life]

That explains a lot... Do you think the egr modulator can go bad? i checked mine and its clean.

[emsvitil]

That explains a lot... Do you think the egr modulator can go bad? i checked mine and its clean.

They can, but I doubt it.

Without backpressure on the bottom diaphragm, the EGR won't work.    You can test for leaks.....

Remove that hose, and plug in a fuel pressure gauge with a long hose so you can monitor the back pressure while driving.

You need to see at least 1/2 psi at the 25mph 2nd gear, steady speed for there to be EGR to lower the NOX.

With my 86,  it just fluttered a little until I added my 'special' back pressure gasket and it went to about 1 psi....  (this is how I aced the NOX last smog test)

[Yota4life]

I have a flange between my down pipe and cat. Im going to make a plate and try your back pressure trick for my next test. I should be good to go after that with a new o2 sensor and some denatured alcohol in the tank  

[emsvitil]

Retard timing 2.5 degrees (you're allowed +- 3 from stock)

[Yota4life]

i was going to do that also. I guess my timming was at 6* my first test

[Yota4life]

Retard timing 2.5 degrees (you're allowed +- 3 from stock)

i did a retest today and with a exhaust plate with a 1.25" hole in it i got closer to passing but still failed. SO i need a better CA legal cat and i should pass fine... thats all i can think of to do now.

[954toy]

how did you do? what was your fix?

[ascdub]

wow good article time to start on the checklist everything in this post are alot of the problems i've been having. Does the airflow meter have any effect on this problem?