OK, took my TBs off for general clean, and decided to paint them high gloss red. Took everything apart and set them up again nice. Well they were nice off the car anyway. I took photos on camera of how they looked before and after to make sure I had it all correct. I did!!
They look good now, put them back on the car, and re-wired all the computers back up, started car, no warning lights - excellent!
However, when I removed the TBs and the inlet manifold, I also removed the thin gasket that connects to the head over the inlet manifold studs. It looked a bit grubby and worn (its green).
I used the same gasket when I replaced all the TBs, however, now the car seems to be a bit laggy, and at the top of the rev range, the engine seems to become 'unbalanced' and makes a harsh vibrate sound. Round town its fine, but when you ut your foot down it still goes, just makes this annoying noise, and doesnt seem quite as responsive.
Should I have replaced the gasket? Could the symptoms I've supplied point in the gasket direction?