90ED6LSV

Ok so my car is a 1990 Civic DX with a 91 Integra B18A1 engine. I was lucky enough to find a smog shop that doesn't realize what kind of engine it really is. Car has a like 8 month old cat that was just sitting for a few months, stock P75 ECU (car has obd0-obd1 ecu harness but has all engine harness plugs changed to obd1) stock Civic intake, stock LS header, etc. Every time ran NGK Iridium plugs and 87oct gas.

First smog test failed horribly on the 15mph test they tagged me as a Gross Polluter :angry: But I passed the 25mph test perfect... I did a little research and found out that I had a exhaust leak on the header and no thermostat in the car which would cause it to run cool and rich until the engine warmed up.

So I bought a thermo, tightened up the header bolts, filled up my tank and added 2 bottles of HEET. Went back to the shop and made sure to drive the car around the block a few times at high rpm and left the car idling while I was waiting. Engine was plenty warmed up before getting into the test. Once again I failed the 15mph test by a huge margin (not as bad as the first test, but still a lot off) but I pass the 25mph test with flying colors... RPM's @ 15mph in 2nd gear 2100, RPMs @ 25mph in 3rd gear 2400.

I'll post my emissions numbers in a sec. The only thing the guy had to offer as advice is checking and/or replacing the O2 sensor. Wouldn't a bad o2 throw a CEL? I have no CEL's when I jump the CEL thing either.

FIRST TEST
15mph- %CO2 12.6 %O2 0.5 HC 233 CO 3.05 NO 25
25mph- %CO2 14.5 %O2 0.5 HC 68 CO 0.03 NO 30
SECOND TEST
15mph- %CO2 13.3 %O2 0.4 HC 190 CO 2.16 NO 22
25mph- %CO2 14.6 %O2 0.4 HC 64 CO 0.05 NO 17

As you can see, most of the numbers got better, but i'm still WAY off on CO's and HC's.... He says it's running rich, idk why or how it passes perfect on the 25mph but keeps failing the 15mph.... it's confusing & pissing me off!!!!! Any help & suggestions on what to do will be appreciated!!! I'm considering just giving it to a shop to BAR it and have them deal with it Lol......

tonylovesjdmEF9

just pass it og status like most of us do

4drEF

A lazy O2 won't throw a code.
It just send the signal to the ECU a little later than it should and that does effect your rich lean condition.

Too bad you didn't run the smog without the HEET. Now it's hard to say if that's causing your issue or not.

90ED6LSV

I did, the first test i did without HEET... The 2nd test I did with it, the scores got better

90ED6LSV

I dont feel like spending that kind of money, where I live it's alot more expensive than everyone else. **** costs a minimum of $250 - $350....

eg6cvchatch

Change the O2 sensor. Make sure you don't have an exhaust leak. An exhaust leak will throw everything off. A wrong header can also throw off numbers, because you need the right flow for your catalytic converter to work properly. I'd make sure you don't have an exhaust leak still, since you had one before, the smallest crack will still make your car fail the way it is failing. Any more questions pm me. I'm a 4 year smog technician.