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2G Car Running Rich

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Yepez12

Probationary Member
7
0
May 10, 2020
El cajon, California
Hello, I have a 1997 GSX. Car seems to be running rich. It smells a lot like gas at idle. I had a check engine light and replaced both O2 sensors. Ive driven the car like 3k miles and check engine light no longer comes on, but the smell of gas is still present. Monitors do not set. I smoke tested car through nipple on intake manifold and found a leaking evap valve or filter right around the canister. I bypassed that, but monitors still dont set and car is still running rich. What would be a good next thing to check? Thanks
 
do you have any exhaust leaks?
an o2 sensor just picks up oxygen so if you have air from a leak, getting to the sensor, it will think the car is running lean and dump fuel to compensate. you can be running so rich that fuel is shooting out the exhaust and the sensor won't know.
 
I'm not sure what you mean by "monitors do not set". Please post your mod list. If it's a roughly stock car then I would think o2 sensor, coolant temp senor or exhaust leak near the o2 sensor.
 
I'm not sure what you mean by "monitors do not set". Please post your mod list. If it's a roughly stock car then I would think o2 sensor, coolant temp senor or exhaust leak near the o2 sensor.
Thank you for the reply... by monitors I mean the readiness monitors required for smog. As for mods, car is rougly stock. Exhaust manifold was cracked and two manifold studs were broken but I just replaced it with a brand new fp manifold and gaskets and replaced all manifold studs. O2 sensors have been replaced. When I smoke tested the car I did not notice any smoke on exhaust side (smoke machine was hooked up for like 1 hour). I do not have a scanner good enough to check values for me to be able to check actual coolant temp. The gauge reads ok though. I think next step will be to just replace the coolant temp. sensor.
 
do you have any exhaust leaks?
an o2 sensor just picks up oxygen so if you have air from a leak, getting to the sensor, it will think the car is running lean and dump fuel to compensate. you can be running so rich that fuel is shooting out the exhaust and the sensor won't know.
Thanks for your reply. No exhaust leaks. I smoke tested the car for like an hour and no leaks were found on exhaust side. I did have a cracked manifold and 2 broken manifold studs but have already been replaced. Someone commented about the coolant temp sensor possibly being bad. I think I will just replace it since its not expensive and go from there. Also, car smokes a little. When I replaced the exhaust manifold I noticed that there was some oil coming from exhaust port #4. I dont know if that could cause this running rich problem.
 
For future reference I use a simple Bluetooth obd2 reader and a cellphone app to read basic functions. Beyond that I would breakout the laptop for ecmlink as I have that. Old reader is quite capable for simple stuff and it's cheap.
I use this one. Yes it reads coolant temp. Your gauge reading correctly does not mean ecu gets good data. They use separate sensors.

Bafx Products - For Android Only - Wireless Bluetooth Obd2 Scanner Diagnostic Code Reader & Scan Tool - Scan, Reset & Clear Car Check Engine Light
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I'm not sure what you mean by "monitors do not set". Please post your mod list. If it's a roughly stock car then I would think o2 sensor, coolant temp senor or exhaust leak near the o2 sensor.
do you have any exhaust leaks?
an o2 sensor just picks up oxygen so if you have air from a leak, getting to the sensor, it will think the car is running lean and dump fuel to compensate. you can be running so rich that fuel is shooting out the exhaust and the sensor won't know.
Also, forgot to mention car smokes a little. When I replaced the exhaust manifold I noticed that there was some oil coming from exhaust port #4. I dont know if that could cause this running rich problem. Im also, thinking about replacing valve seals and if smoke problem persists then think about doing piston rings in the future.

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For future reference I use a simple Bluetooth obd2 reader and a cellphone app to read basic functions. Beyond that I would breakout the laptop for ecmlink as I have that. Old reader is quite capable for simple stuff and it's cheap.
I use this one. Yes it reads coolant temp. Your gauge reading correctly does not mean ecu gets good data. They use separate sensors.

Bafx Products - For Android Only - Wireless Bluetooth Obd2 Scanner Diagnostic Code Reader & Scan Tool - Scan, Reset & Clear Car Check Engine Light
You must be logged in to view this image or video.
Thank you very much! Will definetly look into that.
 
Does your oil smell like fuel? It did for me and later found 3 valves weren’t seating properly because they were out of round.
Actually I just smelled my oil cap and inside my valve cover and it does smell like gas. How can I check the valves for that?
 
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