159 Cruiser and
AO Silver Member
Join Date: Jul 2012
Location: United Kingdom
Believe a failing/ failed EGR will hide faults with the MAF, especially with most posters saying a new EGR resolved most of the issues with power.
If the MAF is going faulty, it'll send the EGR crazy, as it works with the MAP to adjust the ratio of Air/ exhaust, in normal mode, when you put your foot in the accelerator, the EGR should shut, so even when a faulty MAF, you car will just run a bit rough.
To be fair, think as the EGR gets gunked up, it's response slows down (the solenoid on mine was jammed, so up to this point it would gradually slow down). So that quick opening / shutting doesn't happen as it is slowed down by the gunk, so masks the signal, but think it kills off the EGR quickly.
When you put in a new EGR, it can move pretty quickly, so will respond quickly to requested movements, and so the ra ra ra, is the new EGR responding quickly (am making assumptions here).
Had the same issue with mine, the performance dropped off, cleaned the EGR, and performance seemed to improve for a couple of hundred miles, then failed again, with the MAF this time (EML, smoke etc). New MAF put in, and the EGR was totally stuck open again within a week, new EGR and issue has disappeared.