Yep. You're tryin to cut corners with an engine,designed with really tight tolerances. Im in same predicament with my gearbox synchros,but am spending a painful £1k to let ford do it,& get proper OEM parts. Dont like doing it, but i know i'll get another 100k out of this box,maybe more. Ive done the EGR blanking before,& about 4months later regretted it as it was only masking the real problem. Found that along with remapping & not havin upgraded icooler,there was bore-wash etc,& the engine was running at silly temps. Is your car remapped by the way?