Misfire

[Sgt_Lemon]

Just took the car down the garage to check the co after doing the timing. The guy has said that the hc emissions were ridiculously high. Recommended range is between 300-500 and I scored 1800. Thinking misfire, any suggestions. Possibly coil breaking down or the distributor oscillating causing the spark to jump? Co was 0.218

[Mr Blue]

Misfire would be noticeable.

Running rich so could be ignition timing or maf might just need adjusting.
Even an oil change helps with emissions.

Fussy digifant engine.

[Sgt_Lemon]

Had an oil change done last weekend along with ignition timing, did mess up the fuel mix screw on the maf trying to smooth the idle before trying timing. It's what I went to the garage for but there was a break down in communication where he just done an emission test for free. Minus a co reader is there a better way than just vibration smoothing according to rj's guide?