2007 Fit, manual, 400 000km (248 550mi).

Question: if I get a straight pipe put in, are there any other considerations regarding the operation or the car? Will anything else need to be tweaked or adjusted, like computer, fuel injector, etc? I don’t care about performance, I just don’t want to make a change that will cause the vehicle to fail prematurely.

Background: Cat hasn’t been working for over 3 years (makes check engine light come on about 60% of the time, then it’s randomly off again, then back on). Replaced muffler 1.5 years ago and it already has a hole and needs to be replaced again.

I’m thinking of having the cat and muffler taken out and a straight pipe put in. Cheapest one they have. I don’t really care about suping up my car - the old beater is only good for maybe another 1.5 years tops.

My logic is that a straight pipe might save me some money. Less welds and weak points to fail than what you see on a muffler. Might as well since cat is finished anyway.

Emissions/safety inspections are a non-issue. Don’t need to do those.

Is this sound logic?

 

As long as everything you do is downstream from the O2 sensor, you should be ok. You probably won't be removing the cat, I think that is upstream from the O2 sensor. If your b-pipe isn't rusted through, just straight pipe it from the axle-back maybe?

It'll be loud... your neighbors might not like when you come home late at night... so yeah be ready for some noise. As long as you stick to the factory diameter though it shouldn't have any issues with back pressure etc.