Engine 93 GT EGR spacer rear coolant tube routing? Smog help

93foxbodygt

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Jan 28, 2018
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Hey guys, I’ve been working hard on trying to get my car to pass smog here in CA, and failed part of the NOx portion of the sniffer test. This is after replacing/repairing a number of parts.

I have replaced O2 sensors / o2 wire harness, CATS, spark plugs wires, egr valve/ egr sensor, pcv valve, connected hose w/ check valve to h-pipe, and tried to identify any broken vacuum hoses.

But I just realized that THIS rear coolant hose coming out of my EGR spacer is capped off. I know it connects somewhere on the lower intake manifold but I cant see where is goes and I’m not sure what I’m looking for??? I’ve searched online for what the connection looks like, but no luck so far. I think I need it connected, for my EGR valve to function, and hopefully pass smog.

Does anyone have a pictures or diagram of where this hose connects? I’d really appreciate any help. Is it accessible or do I need to take off my upper intake manifold?

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The connection point is on the rear heater feed tube opposite of the one that feeds the front EGR coolant line.
 
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Thanks guys! I’m trying to figure out why I’m still emitting high NOx on the sniffer test. Engine was running somewhat lean after I replaced the above listed parts. Since it last failed I’ve also replaced the ECT sensor, cleaned the MAF sensor, and cleaned IAC port, and am gonna replace the gasket.

I figured the EGR may not be working correctly without this coolant line? I also thought I may have a dirty/faulty fuel injector.. When I did the cylinder balance test, it gave me Cylinder 7...

I really wanna pass emissions. Was thinking about Seafoam to clean fuel injectors and fixing this coolant line. Any opinions?
 
It's 3/8" npt into the manifold and whatever barb fitting fits that line. It's purpose is to cool the egr spacer. The egr itself is vacuum operated by a solenoid on the pass strut tower. The coolant has no bearing on its operation
 
Also, I would change the temperature sensor for the ECU, not the one that goes to your gauge. It tells the ECU that the engine is hot enough. Make sure you have a 192 or higher thermostat. The car will go into closed loop mode around 185 degrees and utilize your new o2 sensors.
 
I've seen multiple sources confirm that closes loop happens at a lower temp than you think. Of course it's also dependent on other variables as highlighted in the "very useful" link.

Regardless, if you really do want the best shot at passing emissions, you want that engine hot. So a 192 might be a good recommendation

I personally run a 180, and my cars temp stays rock solid at 188 degrees, but I don't need to pass a sniffer anymore