93 Camry emissions failed NOx - Toyota Nation Forum : Toyota Car and Truck Forums

galeff · 06-03-2007, 02:01 PM

My vehicle is a 93 Camry 2.2 A/T 170K miles. It just failed emissions – NOx failure. Per the paper given me it lists EGR problems, abnormal operating temp, air management, lean mixture, catalytic converter, advanced timing. There are no codes coming out of computer when E1/T1 method is used. Two years ago, the vehicle passed no problem. Since that time I had a temp sensor go bad causing stalling. Replaced it (with the help of this forum) and had no further problem. That incident however, did make me get after many items that I have neglected. I replaced the PCV valve (the rubber grommet to hold it in was almost dissolved), wires, dist cap & rotor, air hose, but stopped short of going after the EGR system because of what looks a good deal of work. A can of starter fluid will help find vacuum leaks if any but I am hoping that someone has had this and can point me down the express route to determining the cause. I have the factory manuals, owned and worked on my own Toyotas for about 20 years. One more thing, I can’t seem to find the VSV. The book makes it look like its under the exhaust manifold shield but it can’t be that easy.

Stillrunning · 06-03-2007, 04:47 PM

My FSM is for a 95 but my Haynes shows the VSV under the exhaust manifold shield as well. The test for the VSV does not require that you access it. It describes installing a 3-way union in EGR vacuum hose and using a vacuum gauge for the test. Is that what your FSM instructs?

galeff · 06-04-2007, 11:17 PM

Thanks for posting. Yes, same procedure on my 93. I was looking ahead at the inspection paragraph and of course at that point it needs to be out of the car. I'm sure I will need an EGR valve. If the rubber around the PCV valve dissolved Im sure it probably isn't a very pretty site inside the EGR Valve assembly.
Thanks again.

Stillrunning · 06-05-2007, 05:43 AM

Quote:

Originally Posted by galeff

I'm sure I will need an EGR valve. If the rubber around the PCV valve dissolved Im sure it probably isn't a very pretty site inside the EGR Valve assembly.

I would try to remove the EGR and clean it first, I think they are quite expensive. When I got my 95 the PCV grommet was also deteriorated but the EGR was fine, it just needed cleaning. I have always just cleaned EGR's never replaced them. You may need a 15/16" 1/2" drive crows foot to remove the large nut that connects the EGR to the exhaust, but the rest is pretty easy. B12 Chemtool to help clean the carbon off as well as a hand vacuum pump to open the valve to aid in flushing and cleaning.

galeff · 06-17-2007, 09:01 AM

The car passed vehicle emissions the other day and cleaning the EGR valve did. I couldnt believe how much stuff amassed on such a large opening but 170,000 miles will do that. All the emission readings dropped significantly back to where the car was probably 2 to 3 inspections ago. I sprayed a product called Power Blaster on all the nuts the night before working on it to loosen any rusting or seizing. I was able to use my combination 24mm wrench (open end side of course) to break loose the pipe nut. Long handled wrench at a bit of a sharp angle but steady pressure, not jerking it or hitting it with a hammer, broke the pipe nut loose and the rest was history. Scraped what I could off and cleaned the rest with brake cleaner. Tested the valve/vacuum actuator with a hose and reinstalled. Saved me untold amounts of time and $$$.
Thanks again for your interest and information.