I recently replaced a cracked stock exhaust manifold on a '94 ka24 2 wheel drive and found that a set of pace setter equal length headers was $100 cheaper than an oem replacement. So I went with the headers and kept the stock cat and muffler. The reason being I've been in V8s all my life and don't know if I'll like a 4 cyl exhaust note. Well all that aside I have an annoyingly loud bass resonance being created in the cab. My guess is this is due to the headers paired to the restrictive stock exhaust. I have two questions, first will a high flow cat help relieve some exhaust flow suppressing that resonance? Secondly, if not should I do a cat/muffler combo? My only concern is ending up sounding like a civic si because its a four cylinder. Can I get a exhaust that won't sound like a civic? Ok thats three, sorry and thanks for any help.