Emissions Woes Options

[The_Chazzman]

Hey all! Just discovered this site whilst trying to find information on how to clean out my EGR system and get rid of that CLE. I just bought a 96 about 2 months ago and love the thing. I've already had to replace pretty much everything related to power steering except the rack and have had to replace a few gaskets and seals so now she's leak free, the only problem I'm having now is that CLE which, according to the computer, is due to a problem somewhere between the MAP sensor and EGR valve, which are both good and I've checked and replaced. as needed, all of the vacuum lines between the two and still have the light. On top of that, when I fire her up she spits out a nice plume of white smoke and idles at about 1200 until I start moving. After that, no more smoke and regular idle speed. If anyone has any thoughts or suggestions, I am open to just about anything at this point. Thanks.

[Bitter]

year and model?

[The_Chazzman]

Oh, crap! I'm sure that would be useful info. 96 Celica GT.

[Box]

I'd check the EGR modulator, the membrane likes to tear over time. It's easy enough to test, along with the EGR temp sensor and the solenoid. There's the factory testing protocol somewhere on the internet I had found when I got an EGR code, but mine ended up being that modulator.

[Bitter]

Most of the time it's almost always the modulator. If it's not then it's a blockage somewhere. You can test the valve and passages by connecting manifold vacuum directly to the EGR valve at idle, it should be able to make the engine run like **** and stall.

[The_Chazzman]

Thanks a ton! I'll look into that modulator.

[Smaay]

actually in my experience it the VSV under the intake manifold. what is the code you are getting with the CEL. typically its P0400 or P0401. that is the VSV

[nics]

I had the P0401 problem last month. Seafoam fixed it, and I used 1/2 of the can through the vacuum line.

If seafoam still can't help, replace the modulator first then the vsv. The modulator costs about $20 and is easily accessible compared to the vsv.

[Box]

It's been awhile but I had found someone on Ebay that had the modulator new for $15 or so shipped. Much better than the crazy amount everyone else wanted.

[Bitter]

actually in my experience it the VSV under the intake manifold. what is the code you are getting with the CEL. typically its P0400 or P0401. that is the VSV

I've seen one or two failed, but I've done 4x as many modulators. If the code is insufficient flow then it could be any number of things causing low or no EGR flow, from blockages to the valve not opening, to the valve not opening enough. You need the VSV, modulator, valve, and clear passages for the system to work, any one failure can cause a code to set.

[The_Chazzman]

Yeah, it was P0401, insufficient flow. I will give that modulator a crack and I will try out that Seafoam idea. I work for a certain auto parts store so I'm not too worried about the price. If that doesn't get it, I'm not sure I'm up for getting under the intake until I'm positive that I need to go after the head gasket. Since I'm able to register without emissions, I'm not going to go digging for the VSV unless I have to. Thanks, everyone! Most helpful!

[Richardkwon]

Guys where is the VSV located? I bought the part 25860-74050 and the manual shows that it's underneath the heat shield at the front of the engine?