Photo of EGR carnage

[beachcomberspi]

I bought a used ECU and the problem went away.

 

[jatree]

The EGR modulator can melt if it's internal diaphragm develops a leak. When that happens, blazing hot exhaust gas is constantly leaking through the plastic modulator. A new modulator won't melt.

That's what I thought but my 8-month old EGR modulator just melted again. When I picked it up from Toyota previously, I asked if it's possible a clogged cat could cause it do see too much pressure...they said no but I think they were wrong. Luckily being replaced under warranty but now I'm thinking it's time to learn how to assess exhaust back pressure.