Bingo!

Low EGR action = higher NOx output and guess where the earlier 22REs fail, high NOx. My guess is the test is somewhat targeted at getting the older engines off the road. The later 22REs have the ECU open up a VSV to actuate the EGR valve/modulator so that is a more direct action rather than the more passive ll-vacuum setup on the early 22REs.

I know one guy who keeps a set of 28" tires to put on my 4Runner for smog testing. Smaller tires with the 35" tire gearing ups the RPMs for the dyno test.

The other biased part of that dyno test is the dyno. I think they use the same load for all vehicles, so my little 22RE is nearly floored to spin up the tires/dyno while some big motor domestic rig is barely off idle to do the same. And guess where else EGR shuts off? At full throttle, engine vacuum drops to 0, EGR operates on vacuum, but there is none so the valve closes.

 

4Crawler, I never thought about any of that before. Well, the part about them wanting to get our vehicles off the road has occurred to me (ie. "Cash For Clunkers"), but the vacuum issue is a concern.

 

I just don't think the early EGR system was ever designed to pass those dyno tests. Mine did perfect on the old idle sniffer test which was the norm back in the days when the vehicle was new. But now with the dyno and 3-gas testing, it is getting harder to pass, especially since the NOx limit keeps dropping each year. And my EGR system works perfectly, but it is just undersized to handle the dyno testing at full engine load. You can easily kill the engine at idle by applying vacuum to the EGR and all the modulator ports are hooked up right and work. I spent a day or two cleaning all the EGR passages in the head, and even ported by header to up the EGR flow there.

 

The 28-inch tires for testing sounds like a good idea.

Personally I just moved away from Ca We don't even have safety inspections anymore in OK, but that could change anytime.

 

just dropped in new engine after 178k miles, erg system completely plugged. Solvent wont cut the carbon, you have to use brute mechanical force, maybe even powertools. Using a coat hanger wont cut it. When its almost clean, solvent will help. When cleaning the egr valve, submerse it in cleaner fluid and operate the valve using slight vacuum. You might even have to do this for a long time to get it to work. Do the same with the egr valve modulator. Continue with the harsh and filthy cleaning all the way to the intake manifold. To do it right, remove all the component from the motor. I removed my carb and cleaned all the way to the intake. Oh, and dont forget the passages from the head. Lots of fun.
good luck.

 

The best solvent I've found for dissolving really tough gunk is CRC 05021 Technician Grade Gasket Remover. But be very careful with it - it will even melt nitrile gloves. Wear eye protection. Don't get it on your skin, or even near any paint. It'll destroy any rubber or plastic too, if left on for more than a few seconds. But if you can remove the metal tubes to give them a good soaking, it's worth a try. Just keep soaking it and giving it time.




Forget Permatex's Gasket Remover - I still have a can of the old formula and it's great; but they changed the product to make it "safe" and now it wouldn't remove wet paint.

 

That thing sucks to try to keep clean...luckily I don't need to worry about emissions because it's kind of a losing battle to try to keep it clean. You get carbon buildup all over, especially at the exaust, and the pipes leading all the way from the exaust over to the intake.

Good luck!

Cleaning the valve itself is the easy part.

 

I merged three EGR cleaning threads together here.

To those of you that searched to find the threads, THANK YOU!

To those of you that didn't, PLEASE DO SO.

Fink

 

SPAMMER = Ban Hammer

Fink

 

Well, there are several aspects to "EGR being OK". First is as you tested with manual vacuum application, so the valve diaphram is working. Now you need the automatic stuff to actually apply that vacuum at the right time, so you can have a perfect new EGR valve but if it is never told to open, then the EGR system does not work, even though the valve is 100% perfect. Then if the valve is getting vacuum at the right time and opening as it is supposed to, all may not be OK. Why? EGR passages could be clogged internally such that little or no exhaust gas flows. So you could have a perfect EGR modulator and perfect EGR valve, but if the passages are plugged, then the EGR system will not work as designed.

100% correct. This is exactly how the egr functions.

The temp sensor very seldom goes bad but it does happen. For those of you that don't think egr systems or valves don't clog you are mistaken. It is very common.

As for cleaning, there are many different liquids that will cut through carbon. my favorite is carb cleaner. if your going to let it soak you can also use water. Water is really good for top engine cleaning and cutting through carbon. if you have ever seen a blown headgasket and taken the motor apart you will see the piston and valves are spotless. Or a water injection system, same thing.

Now for stuff that is completely blocked and just a blob of moltant carbon. You just have to get in there and chizel it out. ice picks, flexible drill bits, steel punch, and other sharp metal stuff works good. if what ever your trying to clean can be removed, like a egr tube, you can heat it up with a torch and the carbon melts out like butter. It must be very hot and has to be removed from the motor of you will catch stuff on fire.

Autotek
www.916smog.com
916-723-7664

 

The egr does not make your engine run cooler or hotter. If you delete the egr you will make you combustion temperature hotter and could potentially burn a valve but this is 3000+degree's. The radiator does nothing for this. You can have a high NOX level and have a 100 degree coolant temperature. Egr is not just operated between 40-60 mph. It depends on your throttle angle. It could come on at 1mph. It works at slight throttle angles.