Hey guys. I just picked up a 93 Accord EX Sedan. Its quite loud. It appears they removed the cat and replaced it with straight pipe, but used clamps (HUGE LEAK)...ugh! The flex pipe has a huge leak as well. The pre cat O2 sensor is missing. They have it plugged up and I don't think its going to come out to just put an o2 sensor there. My questions is should I replace the entire down pipe all the way and just weld up where the cat is? (I know its illegal) or is that o2 sensor that important? The car has a CEL I haven't had a chance to check it out yet. I am assuming its the o2 sensor or the cat. It runs pretty well but has a hesitation at low rpms. Its just a daily driver doesn't have to be perfect just want something thats get better gas mileage that my G35X (18.5) lol Any help would be awesome. Thanks guys.

 

There is only 1 O2 on your car, replace it this probably the reason for the CEL. I would go to the local bone yard/ Ebay and pick up a used Down/flex pipe. As far as the cat goes i would replace it with an inexpensive direct replacement cat. I am not one for polluting. Here is a link to used Honda parts on Ebay http://stores.ebay.com/id=79528253&s...STRK:MEFSX:SST i use them all the time and have seen the down /flex pipes on there for a reasonable price.

 

Thanks! Also think it's the reason for the hesitation? Also does it have to come off a 93 EX/SE exactly or does that part matter?

 

The O2 sensor is what tells the computer if it has the correct A/F mixture. Without it the computer is just basing the fuel inputs off pre programed tables that are 'safe' for the engine. This will not net you the best power or mileage.

Not sure if the 90-93 models used different manifolds/downpipes/flex pipes between the submodels. You can verify the numbers by going to Majestic Honda and looking up the various years/submodels.