abcdefg123

I have a 95 Honda Civic Coupe EX 1.6L that I use as a DD. It's not mint, and it's not modified but it gets me around town. Recently something clogged up and we are thinking it's the Cat. It's currently at the shop which replaced the Cat about 8 months ago but they say it might be another Cat (The owner said this, he isn't a car person). Now questions. How many Cats does the car have? I've only seen the one right before the Resonator. Second, instead of spending xxx.xx on a new one (We just put 1,000.00 into it for various things) would running a Test Pipe be okay? Will this trigger a CEL? NJ recently stopped doing severe inspections, so since my girlfriends modified cat-less STI can pass, I'm sure the Honda wouldn't be a problem either. Thanks!

94EG8

test pipe wont throw a CEL on an OBD1 vehicle. If you went through a cat in 8 months though you might want to check out your O2 sensor, your probably running rich. There is only one cat btw.

abcdefg123

Thanks. Yeah I thought there was only one cat cause I've never seen a second one. I guess he thought it was a newer car. Is there a good supplier for the test pipes? I've so far have only checked Ebay so I'd rather be safe. Also how would the 02 sensor cause any problems? I could be running rich, gas mileage has been less then great lately too.

Jockone

What kind of warranty did you get on the cat they replaced 8 months ago?

abcdefg123

My Father had it replaced but after talking to the shop it seems like they have excuses. I overheard something like "When the car overheats, fluid leaks into the head gasket and goes to the cat and can ruining it". I feel like that one was thrown out there because I had the car brought to them for a overheating issue I couldn't figure out (Wound up being the stupid radiator cap, idiotic me for missing that).

Today I took the resonator off because I was replacing it since it had a leak (Warranty) and the pressure felt fine coming from the cat while the car was up in the air. So I'm thinking it actually might be something else, here's what the car is doing:

Cold start, the car runs rough and sits at low low rpms (200) and after a minute it jumps up and goes to 1,000.

Idle fluctuates, it will jump around from 400-800.

Before while sitting at lights it would drop down to about 200 and slowly start dying and the car would vibrate. After a few seconds of dying it sounds like the car is about to die and it jumps back up to about 400/600.

During weird/low idles when taking off it sounds like the car is backfiring at times, it's hard to explain but it's not actual backfiring or at least I don't believe it is.

Lastly the car runs with less power, it feels like something is def. clogged.

Any suggestions?

EJeff8

You are probably experiencing a vacuum problem. Check your vacuum lines. or do a vacuum test with your throttlebody and palm of your hand.

Referring to your test pipe. Your will run rich, you're obd1 so you won't throw a code. It'll be pretty loud probably, it's illegal regardless of emissions to run without a cat, so if a cop looks under the car and sees, you're ****ed. You cn buy fake cat's that are just straight through. But yeah, it's probably a vac problem and running a test pipe in your situation wouldn't be the greatest idea.

EDIT: Also, if you do run the test pipe, don't ask the exhaust shop to do it. 1. It's illegal so they won't touch it. 2. If they're dicks, they could report your car or confiscate the pipe you put money into. So don't say a word to them.

abcdefg123

I plan to install the test pipe myself, but if the cat isn't bad I might not worry about it at all. I've done plenty of exhaust, hate doing them since I only have ramps but it's no trouble. As for the vacuum test how should I do it exactly? My Father thinks it might be a vacuum line as well somewhere, I just honestly wouldn't know where to look. Thanks for any help!

EJeff8

^Remove intake pipe, start car, put palm over throttle body port.

If the engine dies, no leak. If it stays on, you have a vac leak sustaining the engine.

abcdefg123

Exposed the throttle body port. Covered it and it dies right away, so this is a good thing, sorta. Still runs a little weak, and has a fluttering idle. Any other suggestions?

abcdefg123

Cleaned the FIT, IACV, TB Cleaned. Still low and semi moving idle. I right now have the resonator and muffler off. Is it normal for it to be back firing now? In 1st (AT) I get a hesitation and popping then it clears up. Does this sound like a clogged cat? Also anyone ever use a Ebay Test Pipe or are they junk? Thanks

CivicSD

any straight through test pipe will work. i dont recommend the ones made to look like cats or the "adjustable" ones. Simple straight pipe is best.