Probe engine shudder

[neo]

Hi guys,

My 1996 Probe (Manual) engine shudders noticeably when I put it under load (anything over 3000 rpms) especially going up hills.

I had the engine rebuilt 6 months ago and kept getting a check engine warning code for a faulty EGR valve. I replaced that along with the O2 sensor but the warning light remained. The engine shudder developed a month later.

I've taken it to 3 mechanics now and they are all scratching their heads.

Has anyone got any idea as to what the problem might be?

Neo.