i got a gsr swap in my civic eg hatch
everything passes clean except for the high hydrocarbon at idle
they say to pass is below 100 and
1st: 400
2nd: 300-350
3rd:475
4th: 750(i did the spark plug gap at .052 which is spec i believe)
i believe it could be my timing on my distributor since i got it stolen and they took the distributor so i bought a new one
i also did new ngk iridium spark plugs,autozone oem spark plug wires
injen short ram intake, skunk 2 intake manifold and 2 1/2 catback from cat
also i had my stock header welded to my cat converter(long story)
No CEL at all im running obd2 motor with conversion wire harness to ob1 p72 ecu

please help me out
thanks

 

High HC is one of two things (generally):
Rich mixture
Bad cat

With the conversion to obd1, you no longer have the 2nd O2 sensor that would identify a failing cat and throw a CEL. You'll have to find another way to identify if the cat is working correctly or not.

Check TPS, the idle circuit, and timing. If everything checks out, consider just dumping a bottle of ISO Heet into the tank as a cheat for a retest.

 

well just got back from the smog station
they were diagnosing it all day yesterday
and when i call today they say they couldnt find a single thing wrong
as far as timing it was correct

NOTE: the cat that was welded to the stock header have had line cracks before and i have shop welded it back like three times
also there was one time i was practicing welding a line crack on my cat and i burnt a hole
but i manage to welded it back toegether

if the smog shop cant find anything wrong then i dont know whats wrong too

 

he just told you... since you are running an obd2 motor on an obd1 ecu you lost the post cat o2 sensor which would tell you if your catalytic converter wasnt working properly which could be causing your high HC readings. Since you welded your cat to your header you should try to find another header and a good cat (maybe you have a friend who has these laying around?) and put them on to find out if your cat is failing.

 

do u know if ur cat is gutt'd?

 

all right thanks guys
ill have to ask some of my friends then...

i know nothing about this cat only that i bought it brand new for 200 at autozone and they say its considered the legal one in california

 

i didnt know autozone sold cats?

 

they dont as of 2009