Hey guys I just finished replacing my stuffed diff and exhaust and now the car won't rev past 2k when driving. It's extremely sluggish the revs don't climb at all, it's kind've like a stuffed accelerator cable I guess, it revs fine in neutral just not in gear.

The diff is a 3:27 LSD (it's an EB II fairmont old diff was a 3:08 single spinner), I've done diffs before and never had this problem but this time I didn't have the speedo sensor so it's still got the 3:08 one in, I know it throws the speedo out by a little but what about anything else, could it throw out the shift patterns or something?

you say you did exhaust aswell???
new or secondhand??
did you fit a different cat??
see where im going?

Yeah haha I did and it's got a nice 260 thousand k's on it (exhaust is only a year old though), and I swapped the exhausts/cats as a whole, basically when I swapped them I could hear loose crap inside both the cats but still being attached I didn't see if I could tip it out, the original one had way more loose crap in it so I just assumed the second cat would be better. Plus it was already on the replacement exhaust lol, lazy I know but I have a set of pacemakers that are going on in a few weeks I was just hoping it would be right till then!

yea i think the cat is blocked...

I put the other one back in and it's no better really, I might have stuffed it when it slammed the ground removing it but ah well I've ordered a magnaflow to go in with my pacemakers next week. I think I've done a headgasket too, I tried it with the cat off which helped the wheezing sound but it's still lumpy/sometimes missing and it's losing a tank of coolant every week or so, plus a million other things lol.