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SDS13COUPE · 09-30-2009, 07:19 PM

Okay, I got one. I've been trying to pass the state ref in my sohc for about 2 months now. Here's the breakdown. No check engine lights and I've passed everything really clean except for NOx. It's starting to get on my nerves. Here is the #'s I'm getting.

HC CO NOx
max ave meas
15mph 118 31 26 0.75 0.100.01 799 2371666
25mph 93 20 24 0.63 0.09 0.04 738 199 321

Here is the list of parts I've replaced. Most were just maintenance but they also help.
-plugs
-plug wires
-thermostat
-cts
-fuel filter
-all vacuum lines
-I've also seafoamed the engine(before swapping plugs) and removed the egr valve and cleaned it along with the bypass pipe, and transducer.

So here is the issue. My car isn't getting hot enough. After driving to the ref they check it with the laser thermometer and it only reads between 110 and 130. The thermostat opens and the hoses pressurize, but I just don't get why it fails only at 15mph. I thought it was my fan clutch but after checking 2 other stock sohc's they have the same resistance when trying to spin em. I think I pass at 25 since the rpm's are higher in 2nd gear so the motor heats up more. I think that at 15mph the rpms are too low to heat the motor up enough. The ref even runs the car on the dyno for a minute to warm it too 150 but it still fails. I'm stuck and any help would be appreciated. Sorry for the looooooong post.

09-30-2009, 07:19 PM	#11
SDS13COUPE Zilvia FREAK! Join Date: May 2006 Location: San Diego Age: 39 Posts: 1,403 Trader Rating: (19) Feedback Score: 19 reviews	Okay, I got one. I've been trying to pass the state ref in my sohc for about 2 months now. Here's the breakdown. No check engine lights and I've passed everything really clean except for NOx. It's starting to get on my nerves. Here is the #'s I'm getting. HC CO NOx max ave meas 15mph 118 31 26 0.75 0.100.01 799 2371666 25mph 93 20 24 0.63 0.09 0.04 738 199 321 Here is the list of parts I've replaced. Most were just maintenance but they also help. -plugs -plug wires -thermostat -cts -fuel filter -all vacuum lines -I've also seafoamed the engine(before swapping plugs) and removed the egr valve and cleaned it along with the bypass pipe, and transducer. So here is the issue. My car isn't getting hot enough. After driving to the ref they check it with the laser thermometer and it only reads between 110 and 130. The thermostat opens and the hoses pressurize, but I just don't get why it fails only at 15mph. I thought it was my fan clutch but after checking 2 other stock sohc's they have the same resistance when trying to spin em. I think I pass at 25 since the rpm's are higher in 2nd gear so the motor heats up more. I think that at 15mph the rpms are too low to heat the motor up enough. The ref even runs the car on the dyno for a minute to warm it too 150 but it still fails. I'm stuck and any help would be appreciated. Sorry for the looooooong post.