So I had bought a spec d cat back exhaust and never knew you had to convert to ex style exhaust system. After finding that out I found some headers at the junkyard and ordered a cat so that I could put it all together. After doing so my car has been misfiring on acceleration and I have no codes being thrown and I don’t know what to try. I checked ignition timing, changed fuel filter, and bought a new downstream 02 sensor to make it try to stop it but none of it has worked. I keep seeing you have to extend the o2 sensors but when I try to look it up I can’t seem to find how to do so. All I find is a thing that gaps your o2 sensor. Looking to see if anyone could help me solve this problem because I’m out of options and I have no clue if I even did the swap properly. The car was just fine before swapping out the exhaust parts so I don’t know what’s causing the sputtering

 

Your upstream sensor is needed and if not connected or there is a problem with the readings then that is the reason. Not sure the best way of extending the wires other than getting some long wire and cutting in the middle of the o2 sensor and connector and stripping, then solder, then heat shrink tube it.

 

So I think I found my issue actually. I’m new to the Honda scene so all of this has been new. This being my first car I’ve also got all my experience barely so bear with me lmfao. But I believe my issue is that the o2 bung on the cat is before the cat and not after, which I basically have two up streams in a sense I’m guessing. So I need that relocated behind the cat so it can read the air coming out of the cat not the air before it. Weird because the one I ordered had it behind the cat on the picture but mine is before. I think that’s what it is so ima have to swap my old one on and then figure out how where to put my secondary o2.


scratch that my o2 sensor is behind. Back to square one

 

does anyone know if the upstream and downstream sensors look different? I am currently just running what O’Reilly has and their system says they’re both the same but I starting to think they aren’t. Also my iat did rip at the start of the connector plug but it got soldered back. Idk if that can cause misfiring but that’s another possible thing.

 

it appears that for the DX they have the same connector but diff part number, they look exactly the same even though the part numbers are different on rockauto, for the ex they have diff connectors as well as part numbers for the up and downstreams

 

yea I don’t get what I did wrong for my swap. Everything bolted on well connected all up but it’s just misfiring and hesitating. I don’t want to change fuel pump and a whole bunch sensors when I’m not getting any codes for it. I’m just gonna put my old one on, and see if it is still doing the same thing. If not then I have 0 clue as to what it could have been. I really wanna run an exhaust set up on my car just cuz I like the sound of it. Bums me out knowing I’m right here but my **** is misfiring

 

alright so I switched it and it’s still doing it. So now I’m thinking maybe fuel pump could be my issue but it wasn’t the exhaust like I thought. Reason I believe it is fuel pump is due to when I started the car after switching the exhaust, I let it sit for maybe 20 seconds and then gave it a little blip up to maybe 2.3k and it damn near stalled out, and it did that to me when i first got in the car pulling into the driveway before taking off the aftermarket exhaust too. So ima try to do the fuel pump next

 

did the fuel pump, and it’s still misfiring. Or should I say it’s like choking, idk why but when it misfires it it feels like the car is like stalling out. Ima try to pay attention to the rpms when it happens but it’s super weird and I’m a bit lost on what else I can replace before this thing is just officially cooked lol. Weird thing is that it idles perfectly fine. It doesn’t feel rough at all.

 

so I decided to drive my car 35 minutes away to see my girl and I finally got a code thrown. This whole time it was just my map sensor. So ima replace it and see what happens.

 

Sorry, I'm, new here. My son has a '98 Honda Civic CX hatchback 2 door. The drivers side door panel is a two piece panel and the top part of it broke and he threw it away. I'm looking for a replacement. It is manual locks and windows. Any help would be appreciated. He only paid $800 for entire car so I don't want to spend too much for a replacement door panel.

 

I don’t have a hatch but none the less the doors for all the 2 door civics, quote me if I’m wrong should all be the same as long as it’s manual locks as well. I’m sure if you go to a junkyard they shouldn’t charge you more than 30 bucks for it. You could always just look for your specific car and take it off one of those if there is one but I’m sure even the two door civic should have the what you need

 

If you just changed to a header from an si civic, you'll be missing your cat altogether, what you want to do is weld an o2 bung on cylinder #4 exhaust about 8" of exhaust travel from the head. Pull the hazard fuze for 10 minutes and then reinsert the fuse and start the car. Hold the throttle about 2500 rpm until the fan turns on then hop in and take a drive. If your car runs rich what you can do is put a spacer on the primary o2 sensor and repeat the ECU reset.

The OEM wire colors are different on the two o2 sensors solely for identification on the wiring harness heading to the ECU. There's nothing different about one over the other and the connectors are interchangeable. You will run into an issue if you connect the primary location o2 to the connector for the secondary o2 and vise versa as the voltage read on the primary will be lower than the secondary, sending your car into limp mode.

If you take the o2 sensors out, it doesn't matter which one goes where so long as the one closest to the cylinder head is connected to the primary plug.

The first o2 sensor measures voltage against the post-cat o2 sensor, so when you remove the cat you're getting too much oxygen on the sensor, the ECU will add more fuel to compensate, and to protect against detonation, will set of the CEL and go into limp mode to protect the engine.

 

I have the normal ex down pipe but I actually ended up solving the issue. None of it was the exhaust and I did actually set it up all properly. It ended up being my map sensor lmfao. Changed it and she’s running all perfect again. I guess it just decided to go out on me after I swapped the exhaust causing me to go into panic mode lolll. I appreciate the input tho cuz I never knew how to distinguish the o2 sensor's from one another so thank you for that. It’ll help in the future.