Ok car is a 91 civic with a h22a swap. I bought it half done and got it running for awhile but it wasn't making power. The t-belt shredded and i founded bad cylinder scoring so i replaced the motor with another h22a. I discovered the previous owner had used the stock obd0 d series injectors so i replaced them with obd1 prelude injectors. The car starts and runs now but runs very rough and makes no power. Sometimes it seems to run almost right for a bit but only for a few minutes. It sputters and seems to miss, and falls flat on its face if you give it gas. its throwing code 12 and 41, egr and o2 sensor heater, but i dont think that would cause these problems. When i pull the pulls the ground straps are bright white. does anyone have any suggestions?

 

clogged egr can most def cause a car to run bad. 02 sensor shouldnt really affect it. id look into the egr situation first

 

The egr is blocked off and non functional. It always throws that code since theres no way to operate egr in the civic.

 

You shouldn't half *** it or it is always gonna run like ****. Either completely convert it to obd1 and run the necessary wires and components for egr or get a tunable ecu and get it to run without egr.

 

i didnt half *** it someone else did and im trying to unhalf *** it. it is completely converted to obd1 and ive never heard of anyone running an egr system in a swapped 4th gen. the wires are present and plugged in but the valve is deactivated. a code 12 should not cause these kinds of problems and deactivating egr won't cause problems either.

 

It's probably stuttering because the oxygens sensor works sometimes and sometimes it doesn't because the heater isn't working right. I assume you've replaced the oxygen sensor ?

What ecu are you using ?

 

p13 ecu, i havent replaced the oxygen sensor yet but im going to as soon as i can. I have them go bad before and this is much worse.

 

If you keep having to replace oxygen sensors then it could be a wiring issue. You should check for continuity from the oxygen sensor connector back to the ecu connector. Wiggle the wires to see if there's a problem somewhere. I assume that that civic uses a 4 wire oxygen sensor? If not, then you should add the necessary wires. You can most definitely get the egr to work. You just need to get the egr components(egr solenoid, egr valve, vacuum control device, lift sensor connector) for a prelude, it can be any prelude 92-96, even the base model, and while you're at it cut off the pigtails from the prelude and wire it into your car. You just need some 16 gauge wire and some ecu connectors to use the spare pins.

 

I can't find a single example of anyone using egr in a swapped 4th gen civic and everyone else runs fine without it. I didn't mean that i keep having to replace o2 sensors i meant on other cars. A car with a bad or no o2 sensor is still driveable, just not running at its best. this car is completely undriveable because it is sputtering and choking so bad. the rpms won't even increase if you give it gas. I noticed i have 2 plugs in the back of the motor that will fit the knock sensor. does anyone know what the other plug is for?