just bought a car 1996 civic ek obdII, d16y8, the car ran terrible when i got it so i changed the cap and rotor and plugs ext, tune up, now it runs better and fine, but still not to its full potential, so the check engine light was on and i checked everything out and found that the o2 sensor was missing off the catalic converter, well actually there was no cat so the plug for the o2 sensor was empty of course, i put a sensor i had spare and just tucked it by the side, i plugged it in and the engine light is off now, is this a good idea driving the car w/o o2 sensor in the cat or a bad idea bcuz i still think the doesnt run the best, ohh and does anyone have a clue how many o2 sensors this car has , im guissing 2 but im just a kid.

and would it be a good idea to buy those cheap 130$ exhaust kits from ebay with the manifold downpipe and whole cat back, basically the whole exhaust system, there cheap but i dont trust the quality, but then im not running a 200hp car so why not right.

 

its not a good idea to do that to your 02 sensor, what it does is sense the A/F and adjust fuel and timing. It allows your car to run normal, if you do that, your either be running rich or lean. not a good idea.

I've only had experience with the ebay kits once and the piping was fine, the headers sucked, and the exhaust sucked.

 

thx alt civicstar

 

With OBDII you have two O2 sensors. One before the cat and one after or in it.

The one before the cat is necessary for A/F. This one the ecu uses for adjusting the A/F ratios

The second one's job is to keep an eye on the cat's condition and that is all.

You should either get a cat with the O2 bung in it or get an O2 simulator.

 

why does it mater about the second o2 sensor by the cat, does it matter if i dont have it in the cat or does it, thats what i need to know so i dont f up my engine u knwow

 

If it is throwing a CEL then it would mess with things.

All the second O2 sensor does it check for the cat's efficiency.

No CEL then you should be OK

 

whats a CEL

 

Check Engine Light.

If it is on you are in "limp mode" and the ecu is adding gas to keep things safe.

If your check engine light is not working then you can go thru the OBDII port and see if any codes are set. If there are none, then your light is off and your ecu is working off the sensors.

When the O2 sensor is after the cat it does not see any O2 normally and the voltage reflects that. So you have your O2 sensor in open air it is seeing 21% O2 and is responding with that voltage which your ECU see's as a bad cat or O2 sensor.

 

CEL is not on bcuz i put a o2 sensor in the plug just hanging, but before it was on bcuz i did not have the o2 sensor plugged in, there is no place in the cat to bolt the o2 sensor in so i cant do anything till i get a new exhaust, which i might get from ebay for like 200$, and the only reason why the o2 sensor CEL light is off is bcuz i got a spare o2 plugged in.

 

is the switch from obd1 to obd2 differet year for different cars? Like VWs is 95 and obd2 is 96 right? what about honda/acura?

 

yeah allmost all companies have diff times they chgned their cars to obdII(i hate obdII,i hate electronics, im bout to buy a vw bug not. honda changed to obdII in 1996, at least for civic