Hello everyone have a quick question could a bad timing effect rpms? I went to two smog shops the first one everything passed but the guys said in 2nd gear when it's at 25mph it's over 3k rpm but just barely and it's supposed to be under. So he said try another shop so i did and they said the cat is bad. Im going to trust the first shop as it seemed that everything he was using was newer looking. I have a 1998 Ls Integra with a b18b1 its all stock engine wise

 

No, timing has nothing to do with RPM:MPH ratio. That would be gearing or tire size. Do you have stock wheels and transmission?
If your cat is bad, that is another story. You'd either have a P0420 code or you'd fail the sniffer test. If you failed the sniffer test, then you should have a printout of the readings.If you have a P0420 code, you'll probably have to replace your cat.

 

There's some fundamental lack of knowledge going on here by both the shops your going to and you. Rpm is a locked ratio that has to do with physical gear sizes and also tire size. It doesn't change based on how "well" your engine is running... Anyway, 3k rpms at 25mph is about right. About to go drive mine and verify. It certainly has nothing to do with timing belt or catalytic converter.