Car won't pass emissions ECU monitors will not set

[CamaroFred]

Is your EVAP reading correctly?
I think that's what my 100 mile trip fixed and not the O2.
I know I still had one sensor Not Ready,but 2 out of 3 ain't bad.
I am not familiar with your readout.

[Rogue Leader]

Originally Posted by CamaroFred

Is your EVAP reading correctly?
I think that's what my 100 mile trip fixed and not the O2.
I know I still had one sensor Not Ready,but 2 out of 3 ain't bad.
I am not familiar with your readout.

EVAP is still not ready. It is showing live data in there but I don't know if the data is correct or not. I am not familiar at all with that so thats why I'm focusing on the O2 sensors, especially because of the failure I had.

[Rogue Leader]

I reviewed the receipts from both the valvespring failure and the cat converter failure. Neither show the O2 sensors being replaced. cat failure was reported as a code "CAT converter efficiency low" That is something reported by the downstream sensor which i think is the source of the problem.

[camguynj]

Originally Posted by Rogue Leader

I reviewed the receipts from both the valvespring failure and the cat converter failure. Neither show the O2 sensors being replaced. cat failure was reported as a code "CAT converter efficiency low" That is something reported by the downstream sensor which i think is the source of the problem.

Try adding a O2 extension but ONLY to the downstream sensors. That resolves Inefficiency codes.
This is the go to one $15 http://www.bigdaddiesgarage.com/straight-cel-fix.html
or the angled extension if fittment clearance is an issue.

[Rogue Leader]

Originally Posted by camguynj

Try adding a O2 extension but ONLY to the downstream sensors. That resolves Inefficiency codes.
This is the go to one $15 http://www.bigdaddiesgarage.com/straight-cel-fix.html
or the angled extension if fittment clearance is an issue.

Thats not the issue I'm having. I had gotten that code and the dealer replaced the Cat under warranty resolving it.

The downstream sensor now is not reporting Short Term Fuel Trim (per live data), which means the O2S monitors won't set, causing my car to be unable to pass inspection.

[xc_SS/RS]

https://forum.hptuners.com/showthrea...Emissions-Test

Check that out for getting the emissions tests to work correctly. Gotta perform a few 'cold starts' and you'll get them working in no time. Remember to not reset the car and do not clear codes out! Anytime you do either of those things you start at square 1.

I had the evap and O2 sensor heater tests not working correctly because I kept changing my tune lol but after a week of driving the car normally (and not loading a new tune or resetting codes) everything worked correctly and I passed emissions.

Edit: I'm not sure you need to follow the directions for speeds. I didn't and everything ended up working correctly. Just drive normally is my suggestion.

[Rogue Leader]

Originally Posted by xc_SS/RS

https://forum.hptuners.com/showthrea...Emissions-Test

Check that out for getting the emissions tests to work correctly. Gotta perform a few 'cold starts' and you'll get them working in no time. Remember to not reset the car and do not clear codes out! Anytime you do either of those things you start at square 1.

I had the evap and O2 sensor heater tests not working correctly because I kept changing my tune lol but after a week of driving the car normally (and not loading a new tune or resetting codes) everything worked correctly and I passed emissions.

Edit: I'm not sure you need to follow the directions for speeds. I didn't and everything ended up working correctly. Just drive normally is my suggestion.

Someone suggested that on the previous page but I tried it and its not working. I have done over 300 miles at this point and the Short Term fuel trim monitor on Bank 1 Sensor 2 will still not set (despite Bank 2 being set properly), and EVAP is apparently not setting either despite showing proper readings. My car is also dead stock other than GMPP axleback.

[CamaroFred]

Originally Posted by Rogue Leader

Someone suggested that on the previous page but I tried it and its not working. I have done over 300 miles at this point and the Short Term fuel trim monitor on Bank 1 Sensor 2 will still not set (despite Bank 2 being set properly), and EVAP is apparently not setting either despite showing proper readings. My car is also dead stock other than GMPP axleback.

Are you overfilling the tank? You know, trickling fuel in after the nozzle kicked off?
My sister has done that and had a CEL pop up.
Once fuel instead of vapors enters the canister it takes forever to clear.
So she comes home last week and says,"It took me forever to pump in the last $0.75" I said, "So you are back to topping it off when you know you failed emissions last time because of that?" "No, I wasn't" "Yes you were"
She finally has a light bulb moment...
Just a thought.

When the pump kicks off give it up. It ain't gonna give you another day's worth of fuel anyway.

[greyscale]

When I had this problem I couldnt get everything to be at ready until I drove over 60mph then it worked fine and I passed

[camguynj]

Originally Posted by Rogue Leader

Thats not the issue I'm having. I had gotten that code and the dealer replaced the Cat under warranty resolving it.

The downstream sensor now is not reporting Short Term Fuel Trim (per live data), which means the O2S monitors won't set, causing my car to be unable to pass inspection.

The downstream O2 sensors really have no effect on fuel trims. Not sure what the Live data readings mean but I would still try adding a cheap O2 extender to at least one bank
as it can't hurt as they resolve sensor2 CEL codes which cause Not Ready status for cars with LTs and no tune or cars with HF cats

[Rogue Leader]

Originally Posted by CamaroFred

Are you overfilling the tank? You know, trickling fuel in after the nozzle kicked off?
My sister has done that and had a CEL pop up.
Once fuel instead of vapors enters the canister it takes forever to clear.
So she comes home last week and says,"It took me forever to pump in the last $0.75" I said, "So you are back to topping it off when you know you failed emissions last time because of that?" "No, I wasn't" "Yes you were"
She finally has a light bulb moment...
Just a thought.

When the pump kicks off give it up. It ain't gonna give you another day's worth of fuel anyway.

I'm cut from the same cloth as you, it clicked, kits done. I did go and check all the hoses and lines and plugs to the EVAP soleniod and saw nothing awry.

Originally Posted by greyscale

When I had this problem I couldnt get everything to be at ready until I drove over 60mph then it worked fine and I passed

Heh, I wish that was the problem but shes been well over 60 quite a bit.

Originally Posted by camguynj

The downstream O2 sensors really have no effect on fuel trims. Not sure what the Live data readings mean but I would still try adding a cheap O2 extender to at least one bank
as it can't hurt as they resolve sensor2 CEL codes which cause Not Ready status for cars with LTs and no tune or cars with HF cats

I don't think its minor affect matters in my situation (the effect is minor, its based on cat efficiency to offer up minor fuel trim changes for emissions purposes only), the fact its not reporting matters. The Bank 2 one is reporting 99.2 percent fuel burn, Bank 1 is reporting N/A, hence the monitor doesn't set and the car won't pass. Remember I don't have any codes and theres nothing wrong with the primary sensors they are operating correctly. I don't want to start throwing aftermarket parts at the car that are not and shouldn't be needed. For 40 bucks I could just get a new downstream sensor, that could fix it, unless my problem is somehow worse.

[who-dat]

Did you ever get it to pass?



I own a federal emissions business. If you want to PM me I can assist you in passing depending on the software used to test your vehicle

[xc_SS/RS]

Originally Posted by Rogue Leader

Someone suggested that on the previous page but I tried it and its not working. I have done over 300 miles at this point and the Short Term fuel trim monitor on Bank 1 Sensor 2 will still not set (despite Bank 2 being set properly), and EVAP is apparently not setting either despite showing proper readings. My car is also dead stock other than GMPP axleback.

You might need to drive it further than that. I think I drove around 6-800 miles to get everything to set properly.

Evap was the thing that took the longest for me. I found that starting the car in the morning (cold start of course) and driving pretty much right away got the Evap system working. Not sure you need to let it idle for 2 minutes or whatever. So I’d try a cold start and get driving right away as normal. Then, if you hear 3 clicks or taps randomly while the car is still kinda cold, Evap has done its thing.

[Rogue Leader]

Originally Posted by xc_SS/RS

You might need to drive it further than that. I think I drove around 6-800 miles to get everything to set properly.

Evap was the thing that took the longest for me. I found that starting the car in the morning (cold start of course) and driving pretty much right away got the Evap system working. Not sure you need to let it idle for 2 minutes or whatever. So I’d try a cold start and get driving right away as normal. Then, if you hear 3 clicks or taps randomly while the car is still kinda cold, Evap has done its thing.

I've tried driving right away, waiting 2 minutes, and warming the car up :( Thanks for the heads up on the EVAP noise. I have heard that noise before in the past but not recently. I will keep driving I guess but 600-800 miles seems crazy, there is no way it should take that long. Almost everything I have read said one to two 60-70 mile trips did the trick