I fitted an EGR blanking plate to my '99 TD5 recently and the difference was astonishing. On the first two full tanks of fule it was returning an extra 70mls per tank with the acceleration slightly improved.

However, a couple of months on and the improvement has disappeared strangely. I have checked the plate to make sure it hasn't warped but all appears fine. MPG has returned to approx 560mls per tank and performance is sluggish again. Any ideas?

Thanks,

Major Clanger

Hmmm...... I suggest you check the inlet tract, the hoses, and the EGR valve thing too - unless you dumped the lot.

The inlet manifold may be heavily gunged inside after many miles with the EGR pumping filth into it.

If the AIR FILTER nweeds changed, you will notice the power dropping off as the TD5 has an air mass meter, so choked filter means less air through meter means less fuel injected.

Quick test - whip out the filter element, and take her out for a spin. If she goes well, treat her to a new air filter.

CharlesY

Charles, thanks for the reply and my apologies for not having replied sooner, I've been abroad with work.

Filter is fine, it's a new-ish K&N and whilst the inlet manifold is coated in gunge I can't understand why the engine performed so well for a couple of tanks and then dropped off. Hey ho.

Thanks again,

Clanger

NOnethe less, to eliminate a filter problem (like it is wet or oily or got dusted) take it out and go for a spin.

If the thing sparkles you know what to do.

If it makes no difference, shove it back in and look elsewhere.

CharlesY