EGR Excessive Flow code

Hi,

I'm new to this forum and I'm really hoping I can get some help here. It looks like you all share a lot of information.

The other day my check engine light came on, the error code says EGR excessive flow. So I've done some research and it looks like I may need to change the EGR valve, the VSV and the modulator for the VSV. Are these things hard to replace? I'm fairly competent, I do my own spark plug and oil change stuff but I don't have a huge set of mechanics tools or even a garage.

If anyone has a picture or diagram which shows these parts that would be very, very helpful.

1999 Tacoma, 4 cylinder, 2.7 liter, manual transmission, xtra cab.

Thanks in advance,

 

The valve and modulator are on top, near the firewall on the drivers side, behind the intake manifold. The EGR temp sensor is also nearby. Any one of those items could be the culprit. You likely don't need to replace all of it.

Only the VSV is hard to get at, its hidden underneath the throttle body. The temp sensor and modulator are the easiest to get at and replace.

I have an ongoing 'insufficient flow' issue with my truck, similar to yours. Its the temp sensor. I just remove it, clean the tip as good as I can, and re-install. Then the CEL stays off for several months. Eventually, I'll replace the sensor.

If your idle is nice and smooth, then the valve itself is likely OK. Make sure all the vacuum lines are connected and not cracked. If you don't have a Haynes manual, get one. Best thing short of the factory manual.

 

Thanks, I was able to replace the EGR valve without issue (except that I'm short and some parts were hard to reach).

Sadly, even with the battery disconnected for several days the error message came back pretty quickly. I tested the egr vacuum modulator valve and that does not seem to be working well. I have decent air flow on one side and not the other so I'll change it. The thing is to get an exact match I have to pay $95 - $150 but NAPA has an egr vacuum modulator for about $32. Is this an item that needs a specific replacement part or will this generic from NAPA work?

Thanks again.

 

You should be able to get an exact match modulator from a wrecking yard. I think the 2.4 motors also use the same EGR parts for that year. Thats what I did. but it didn't fix my problem, since it wasn't the modulator afterall.

You say that you tested the modulator. Did you follow the directions in a manual? The vacuum that it allows to go to the valve, should be a pulsing vacuum, not a steady one.

 

A wrecking yard may be a good idea. I just thought if I could get something brand new that works for $32 it'd be better than used.

I did the test per these instructions http://www.toyotanation.com/forum/103-3rd-4th-generation-1992-1996-1997-2001/330845-egr-vacuum-modulator-valve-gen-3-camry.html I know it's for a Camry but it seems like it would be the same test, even looks like the same piece.

 

I agree, the test for other model Toyotas should be the same. Good job.

Take a photo of how the modulator is hooked up to which vacuum line (or mark it somehow), unhook it, and take the part down to the wrecker. The same part number is likely used on several different Toyotas, not just Tacoma. Shouldn't cost more than $20.

I did the same thing to troubleshoot my EGR problem. Didn't solve it, so now I have a spare modulator.

 

If you have a spare part than the original will never break.

Thanks for your help.

 

You're welcome.

You know, thats what they say, and I really believe it. For years, I see other rigs break stuff, and then rush out and get a spare. Then never use it. Its really true. Once I used my spare igniter, from my old 4runner, but it was for someone else, whose aftermarket ignition system died. My wrecking-yard spare got him off the trail and back home. He later mailed it back to me. He was one grateful guy. I hope he 'paid forward' the gesture. Also, I carried a spare fuel pump (also for my carb'd 4runner) for years and never used it. One year after I sold it, I got an email from the buyer, saying that the fuel pump died on the trail, and he used that spare pump (saving his day).