EGR Valve and Related Performance
 

I have an SC2 1996 that seems to have a problem with acceleration. After reading many posts here on the issue, I tried a test in disconnecting the wires to the EGR Valve and gave it a test drive. That solved the problem completely. I was convinced to believe that the valve was the problem, so I went ahead a installed a new one. It worked ok for a little while, but it seems that the PCM wants to open the new valve still at the wrong time, perhaps once the engine is warm? The first test drive was ok, but the next one the same day was a problem. Any clues?

My L300 had similar issues. The car ran fine with the egr valve unplugged. With it plugged in the acceleration was very surgy, I don’t think that’s a word, heavy throttle it ran ok, light throttle it was terrible. I restricted the egr flow and all I gained was a check engine light for low egr flow but the car ran a little better. I moved on to the L200 and they don’t have egr. I did sell the L300 with the check engine light on and disclosed that it had an egr issue.
I work on Diesel trucks and egr is a big problem.

Did you clean out the carbon buildup in the pipe that feeds the EGR when you did the swap? If not, you may have clogged up the new one with carbon and oil slime very quickly as now that you have restored proper flow, all that nasty crap would again be able to flow at a high enough velocity to reach the EGR, thus clogging it up.

I doubt a 96 s car made it 23 years on the original EGR without issues. I used to pull mine maybe once every 20 K to proactively clean it and the passages leading to and from it. More often after it began to burn oil.

Use copius amounts of choke/carb cleaner to clean the EGR itself. Make sure the pintle moves freely. Once you're satisfied, repeat the entire cleaning (not kidding.)

To clean out the passages leading to and from the EGR, run the engine for about 2 min to get warm. Turn off ign

Remove the EGR valve and set aside for cleaning as mentioned above.

The rest of this process is much easier w 2 people but can be done w one.

Cover everything under the hood with new unused thick shop rags Something that has not been exposed to anything flammable and something that will not blow away. Keep clear of the belts and the fan. And the throttle body.

With the ignition off, spray the insides of the passages liberally with carb choke cleaner, wait above 3 min, then cover the end of the input tube to the EGR. STAND OFF TO THE SIDE.

PUT ON GOOD HEARING PROTECTION AND LEAVE IT ON.

. THE REST OF THE PROCEDURE INVOLVES RUNNING THE ENGINE WITH RAW EXHAUST AND THUS NO SOUND DEADENING.

Start the car. It will struggle, but when it does start, it will eject brown slimy junk from the pipe that feeds the EGR. It is high velocity, direction forward, but where it lands is anyone's bet. Hence the towel and the protective shop rags if you're doing it alone.

Give the gas a few good crisp punches to expel what's loose. Turn off the engine..

Repeat until you are getting a very small glob of slime at startup. As the engine warms up during the repeated cleanings, you may or may not get a larger volume of scuzz coming out. when it gets hot enough the cleaner will start to vaporize before it can dissolve anything.

With the engine running work the throttle by hand under the hood while spraying choke cleaner into the other tube that is the output from the EGR. Feather the throttle to keep the engine from stalling. Do not burn yourself on the hot exhaust gas coming from the EGR inlet tube.

The method is loud, crude, and effective.

If you don't cover the outlet pipe, consider it abstract art.

Make your EGR valve seals properly.
The gaskets are still available.

Enjoy

Perform at the same time all your neighbors are cutting grass on a weekend with your garage door half shut and if you are lucky no one will call the police for a noise complaint.

interesting advice...I told the clerk at the parts shop about this volcano treatment, and there was much agreement about how effective it is. I might wait until the neighbors insist on blaring rap music from their cars as they often do, but until I can anticipate, I'll just leave the valve deactivated for a while and hope that the car will drive properly in the meantime. It only has 195,000 miles...my mom bought it new and I inherited it about sixteen years ago.