hey guys got a quick question here.
ok several questions maybe.

I have a 94 4cyl camry.
hasn't been driven much in several yrs.
was having issues getting this thing to pass emissions (nox)
and had just put the car away.
well a couple yrs have now gone by and I gotta tag this turd.

so I made sure I put nice clean gas in and ran it to emissions.
failed nox. forgot I dialed the timing back a bit when I last got the emissions.
brought the timing back into time and still failing nox and
strong gas smell from the exhaust. very rich.
took EGR off and cleaned it good as well as the pipe from EGR to block. clean as a whistle. still failing nox and still strong gas smell.
again fresh clean gas. drained it from the tank and ran a fresh tank of gas through to make sure the system was as clean as I could get it.
any ideas here guys? I'm gonna warm the care up and vac test the EGR
to see what I might find.
any ideas from those that have been here? lol

 

I just did both of my cars, one was a 94 camry. The nox was because the vsv and the Vacuum Modulator were both clogged up, just order new ones and make sure the lines are clear too.

Dorman 911-609 EGR Vacuum Modulator
Dorman 911-604 Toyota Vacuum Switching Valve

The gas may be other issues.

 

I'm betting its one of the two you mentioned or the EGR.

I just don't want to start throwing parts at the problem w/o
properly diagnosing the problem.

where did you get your parts at? the dealerships are very proud
of these parts here if ya know what I mean.

 

High NOX is caused by high combustion temperatures.

Check for items that can cause the engine to run lean.

Make sure the engine is not running hot.
Check for air leaks in intake system and exhaust prior to converter.
Bad 02 sensor.
EGR system issues.
Timing.
ECT sensor.

Pickup a Haynes service manual.

Run tests on the EGR system. The EGR is off at idle. What was the NOX spec at engine idle?

Set timing to factory specs.
Check ECT resistance specs.

Could be a bad 02.

 

You can get them from Autozone, but you can get them much cheaper from Amazon.

 

[QUOTE=toyomoho;95942]

Run tests on the EGR system. The EGR is off at idle. What was the NOX spec at engine idle?
QUOTE]

your talking from my emissions test right?
so I'm gonna test the EGR by vac today.
your saying I need to add throttle when I do this or at idle?
if it stumbles but doesn't shut off?
if it just shuts off?

 

Yes, your state may check NOX at idle. The EGR is off at idle. If NOX high at idle problem may be some place else.

Can bypass VSV to turn on EGR at idle. EGR on at idle will cause engine to stumble or quit. If no engine response, EGR may not be working.

 

ok I'm not using a scan tool so I'm guessing I can use the vac pump to do this?

 

dang is this forum usually this dead?

 

Use pump to activate valve.