hey guys, everything is running great or so i thought! Took it to the smog shop, test only here in california and heres was i got

15mph Test RPM 1657......
Co2 --14.19
02 --0.74
HC -- Max 88 - Ave 19 - Measured 165
CO -- Max .64 - Ave .06 - Measured .59
NO -- Max 508 - Ave 136 - Measured 808 FAILED

25mph Test RPM 2651........
Co2 --14.60
02 -- 0.35
HC -- Max 53 - Ave 12 - Measured 71
C0 -- Max 0.78 - Ave .05 - Measured .26
NO -- Max 761 - Ave 124 . Measured 428 FAILED

So , as some of you know, just put on rebuilt heads and headers. k&N FIPK etc etc......... after the test that i faield, took it home and checked the EGR system .....The tube that goes into the Plenum was caked full of Carbon, so i cleaned it all out. Checked the EGR valve seems ok with all the tests that ive done. Temp Sensor on the EGR is working within specs per the FSM..... No vacuum leaks that i can tell. Cat doesnt seeeeeeeem to be that old. Checked and cleaned the 02 sensor, took it out and ran it without it in........no difference.

So basically ive cleaned everything, made sure everything is working per specs . Dont know where to go from here??? only thing i can think of is a NEW CAT and a NEW EGR because everythign else seeeeeeems to be ok.

Pulled codes also....NONE steady flashing blinking Check engine Light.......which if i read the FSM right means all Clear......

Did put a new COIL on because after the Smog test i went tits up on me could a bad coil, cause the fuel not to burn all the way and give all my high readings?


HELPPPPPP by the way 1993 4 runner 3.0 Downey Headers

 

maybe the catalytic? would that cause those kinds of numbers?

 

i had mine fail twice on the no. part of the test also. turned out the egr vavle had sufferer an impact rendering it inoperable. did the vacuum test which showed the egr was in fact, at fault. replaced the egr valve, retested and passed with score of 108 and limit of 735.

if you apply vacuum to the egr, the engine should sputter and generally run rough. if it doesnt, then your egr is at fault. its a bit of a pita to get out as the compression type fittings will be snug, it will take some wiggling to get it out. check out local parts yards for a replacement. normally, they should last for quite a while. hope this helps.

lee

 

Don't neglect to test the EGR Vacuum Modulator and check ports on the throttle body for clogging.

 

Hey, i gapped my plugs at .032 instead of .031 how much of a difference is that going to make???

 

Hey, i gapped my plugs at .032 instead of .031 how much of a difference is that going to make???

 

Now, i'm not an expert on plug gaps, but I can tell you what causes high NOx emissions. Combustion temperatures in excess of 1200 degress fahrenheit breaks the bonds of atmospheric nitrogen. This is usually caused by a lean condition inside the engine. To cool combustion chambers the EGR valve recirculates exhaust gases which are relatively inert, therefore limiting how much oxygen is ingested by your engine, decreasing the air:fuel ratio.

So essentially you need to cool the combustion temperatures by either adding more fuel, ingesting colder air, or cooling your engine (radiator/oil).

There are several components which activate the EGR system, an electronically controlled vacuum switching valve which allows vacuum to reach the egr valve only when the engine temp is above 118 degrees. There is a vacuum modulator which is controlled by two ports on the throttle body, the R port and the EGR port. If either of these two ports are blocked then the entire EGR system will not function. Check out the factory service manual and run through the diagnostic for the egr system at http://personal.utulsa.edu/~nathan-b...77exhaustg.pdf

 

<sarcasm on>
smog test? what are those?
<sarcasm off>
go michigan

 

Taking a second look at your smog results, I suggest getting a new catalytic converter. Both Hydrocarbons and NOx are high which is somewhat contradictive. NOx levels are caused by a lean running condition which would produce very low HC and CO readings. A rich condition would show low NOx levels but have high HC and CO readings.

 

Sorry to hear that Jandk. I'm heading out to dinner, but I'll check my '94 3. slow smog results I recently took and compare results, luckily I passed.

Check out this website that may or may not help interpret readings.

I'll post again tomorrow.

http://www.artsautomotive.com/thesmogstory.htm

 

well, i think i might as well just grab new EGR, 02 sensor, and a Catalytic....... found the egr for 69 $ the catalytic for 75$ and 02 sensor for 50$.........for 200$ i figure all my problems be solved for a while?????????

 

anyone?

 

I had some numbers like that one time. Failed, had to leave. I drove around for about 10 miles, repeatedly bringing the first 3 gears to redline. (back road) Went back and passed emissions with flying colors. If the test is free when you fail like it is here in Oregon, I say try what I did first. If you fail again, then go buy some parts. It is really important to be warmed up enough and get rid of some carbon.

 

OK guys, heres the latest....... new egr, new 02 sensor, and new catalytic ....... checked the o2 sensor, it was outta specs....... 5.1 to like 6.5 ohms was in specs, i was at .5 so thats gonna be a help, the egr when i tap it with a wrench it sputters so i think the valve is stuck open and closes when i tap it..... beat on the catalytic and it sounded like something was rattling around inside when i tapped on it.....so i think all 3 things might be bad! what do you all think?

 

It is possible that all three are bad. I am banking on the catalytic converter and the 02 sensor; it may not be neccessary to replace the EGR valve. To test if the egr is operational take the vacuum hose of the top of it and suck on it, if you don't want to suck on it you can attach it to a manifold vacuum source. Your engine should start to stumble and nearly die if it is working properly.

 

EGR doesnt taste too good!

 

sucked on the egr and it died.........so im assuming its good.......last time i did it, it wouldnt die...........hmmmmm........faulty?

 

Did you do anything to the EGR system between the two trials? And in the case that it didn't die, did it at least start to run roughly?

 

actually i replaced the hose that goes on the reed valve, it was kinked up and i put a 90 deg elbow, since its not in the same spot since the downey headers were put on

 

Alrighty kids....... well just put on the new catalytic ......no more stinky gas smell! Now its clean smellin exhaust, no H2O on the ground , MUCH improved throttle response ......guess a broken up, plugged cat will reallllly screw up your ride if its not flowing right! well, Off to the smog shop in the morning and we'll see just how much better the new cat did for emissions!