95Blue240sx
08-01-2007, 03:35 PM
I have a 96 s14 as a daily driver, auto. It was just bought maybe in february. Story is long so I'll skip that. What happened was we couldnt pass smog because the it wouldnt complete 2 of the ECU checks, even though I drove the car 1k+ miles. Then the head gasket blew and come to find out the rings are bad. I bought a used s13 dohc ka24de, swapped intake/ex manifolds and dropped the motor back in. Drove the car around for a few hundred miles and took the car to get smog'd and it FAILS with too high of Hydro Carbons. I was about ~11 points from passing.
ECU readiness passes, and everything thing but HC passes on low and high speed. When I put the motor in I changed the oil, so that should be ok. I used seafoam through the intake manifold, and then after I changed plugs. Wires are maybe a couple months old, NGKs. Cap and rotor were in ok condition. We did the test two times that day. Once was on 1/4 tank of 89. After it failed added in some octane booster and filled up with 91, drove around a while 20+ miles and retested. HC dropped on the low, but still failed on the high.
From searching google it looks like HC reside in old oil, but I just changed the oil. Other searching on her led me to - Seafoam fouls the o2 sensor, so I should replace it :( and using octane booster is a no no. In regards to the octane booster S14DB's old post says to finish the tank with booster, fill up and use that tank, and then test on the 3rd tank. Another thing I saw on google was tire pressure should be checked before smog, I didnt check it. The front of the car was on stands for a couple weeks while I swapped motors, so the rear tires are pretty low on pressure.
Im hoping that if I change the cap/rotor, 02 sensor, and fill tires to standard pressure Ill be able to pass. Can anyone else shine some light on why the car wont pass the Hydro Carbon(HC) part of the test?
Cliffs: Car wont pass, HC too high on high and low speed test. Will changing the 02, cap/rotor, and filling tire to standard pressure help me pass??
ECU readiness passes, and everything thing but HC passes on low and high speed. When I put the motor in I changed the oil, so that should be ok. I used seafoam through the intake manifold, and then after I changed plugs. Wires are maybe a couple months old, NGKs. Cap and rotor were in ok condition. We did the test two times that day. Once was on 1/4 tank of 89. After it failed added in some octane booster and filled up with 91, drove around a while 20+ miles and retested. HC dropped on the low, but still failed on the high.
From searching google it looks like HC reside in old oil, but I just changed the oil. Other searching on her led me to - Seafoam fouls the o2 sensor, so I should replace it :( and using octane booster is a no no. In regards to the octane booster S14DB's old post says to finish the tank with booster, fill up and use that tank, and then test on the 3rd tank. Another thing I saw on google was tire pressure should be checked before smog, I didnt check it. The front of the car was on stands for a couple weeks while I swapped motors, so the rear tires are pretty low on pressure.
Im hoping that if I change the cap/rotor, 02 sensor, and fill tires to standard pressure Ill be able to pass. Can anyone else shine some light on why the car wont pass the Hydro Carbon(HC) part of the test?
Cliffs: Car wont pass, HC too high on high and low speed test. Will changing the 02, cap/rotor, and filling tire to standard pressure help me pass??