I had my car left at the dealer for general check up, and they say I have to replace the EGR mudulators and EGR valves. What the heck are they? Functions? What happens if I don't have them replaced?
I am quoted about 4-500 dollars just to have the two replaced.
Need some advice...

 

they have to do with smog/emissions I don't know the exact function, but my valve is messed up and its 160 +labor to get that replaced ... I have asked around about it and the valve could just have carbon build up on it and need to be cleaned... but its sort of hard to get to. the modulator is like a 60$ part and you can replace that yourself easy!. its just pushing a bunch of tubes in pretty much ... I have been going or over 5000miles with mine bad and still getting 20+mpg

its just annoying that the check engine light is on.
I also wonder if both of yours are bad. ? did the lexus dealer tell you they were?

 

Yes. The Lexus dealer here in Ann Arbor, MI told me so. And they quoted me 450 dollars to have them replaced?

You had yours replaced for 160? Where at? Probably not the dealer, eh?

 

no I won't go to the dealer they told me I needed new tires(they had 2k miles on them), they told me that my climate control screen was bleeding or whatnot.(it wasn't) they told me I should replace both head light housings because they looked like they needed to be resealed.. which I had just done. I just don't trust them..anyways .. they are more expensive to, the egr valve quote from my dealer was 220 for the part, and around 100$ labor so 320 about. I have not had the valve replaced yet..
I found a good mechanic that I trust and they actually get all there parts from Toyota/Lexus just a little cheaper

 

Or you could get rid of it altogether with block off plates and a resistor (takes care of the check engine light).

I'm not sure if its the same design for the SC400 and SC300. The Block off plates for the Supra fit the SC300---I've got some.

Emmissions may go up slightly, but I've known a few guys that ran through the smog check without EGR.

 

EGR - Emissions control devices (Valve and Selenoid) - i have had to replace them on every one of the jag's i buy and sell. It seems that they are only useful for emission test passing and other then that only cause the check engine light to come on.

J

 

If my EGR modulator or valve goes while I'm driving, will my engine go as well?