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I'm facing an issue with my 2007 Equinox, which is failing its smog test. The primary problem seems to be with the EGR valve not being recognized by the OBD sensor. Here's a breakdown of the situation:
Initial Diagnosis: The smog failure was initially attributed to the EGR valve not showing up on the OBD sensor.
Dealership Mechanic's Advice: A mechanic from a dealership (mechanic 2) suggested performing a Smog Drive Cycle Check. Following their advice, I plugged in my OBD reader, which confirmed the EGR was "off." I executed the recommended drive cycle test (speed up to 55 mph, hold for 3 minutes, slow down to 20 mph, then speed up to 60 mph for 5 minutes and back down to 20 mph). However, the EGR status remained "off."
Repeated Tests: I've repeated the drive test several times, only to find additional issues cropping up – now the EVAP and O2S sensors are also turning off, while the EGR continues to not be detected.
Recent Repairs: Notably, the fuel pump was replaced recently at a different shop (mechanic 1). During this service, they also observed the EGR failure but suggested driving a few hundred miles to resolve it.
Seeking Next Steps: With this background, I'm uncertain about the best course of action. The dealership mechanic's guidance to "just Google it" for the drive test didn't seem to solve the issue.
Does anyone have experience with this type of issue or suggestions on what to try next? Any insights or advice would be greatly appreciated.
Dealership Mechanic's Advice: A mechanic from a dealership (mechanic 2) suggested performing a Smog Drive Cycle Check. Following their advice, I plugged in my OBD reader, which confirmed the EGR was "off." I executed the recommended drive cycle test (speed up to 55 mph, hold for 3 minutes, slow down to 20 mph, then speed up to 60 mph for 5 minutes and back down to 20 mph). However, the EGR status remained "off."
No, that's not right. Avoid dealerships whenever possible.
No, that's not right. Avoid dealerships whenever possible.
This is what you need to do ...
Thank you for this info.
I've tried the provided steps in the PDF closely and here are my results:O2 sensor now on. EGR still off. EVAP also off, but not a concern for SMOG as far as I've read.
I also ran a decel test from 60->0 six times and still no progress. Basically taking the car up to 55-65mph for 3 minutes and decel down to 0.
EGR_PTC % increments from 0->20% while driving
EGR_ERR(%) starts at 99.2% when idle and goes into the negative while driving, see picture
I noticed the OBD device has a warning icon lit as well, unclear why that is yet.
I made an appointment to go back into the dealership as I'm not sure what else to do. I need EGR to be marked as completed in order to pass smog or the car wlil no longer be street legal
Looking for additional tips / tricks. Seems like the decel test should be sufficient after 3 times.
To me, this implies something wrong with the computer itself?
The fuel pump was replaced by a non-dealership mechanic. Weird thing was there is a relay he added off the fuse box in the engine compartment and spliced in with electrical tape. I see no warning light on the dash but my suspicion is that there is some further non-standard repairs breaking the EGR control system / sensors from the computer.
double check the Foxwell manual, but I think the yellow exclamation icon means there's pending trouble codes, so run a full scan. It sounds like your EGR valve isn't working properly.
I went out for a new EGR decel test tonight and before I went out, made sure to reset all codes (non were showing up as stored or pending but did it anyway) on the engine setting of the Foxwell.
I after my cycle of 55 down to 20 and back up to 55 a traction control warning came on which was intereseting. The test on live data went from INC (incomplete) to N/A as did several other sensors.
When I got back, I ran the codes again and saw an EGR error PO0404 (see attached). So this leads me to believe that the EGR valve does have a fault, but it was only visible after (1) resetting codes and (2) a decel test.
Looks to be time to stop doing drive cycles and verify the operation / condition of the EGR.
agreed - I just ran the full test that was given earlier in this thread - works well for everything but EGR and CAT. I removed the EGR yesterday, cleaned it, reset codes and did the full drive test today but to no avail. Going to pick up a new EGR today from NAPA and try that. I suspect that EGR is failing at an electrical level and blocking the CAT from completing its test. Will know more tonight.
December 9th, 2023, 1:07 AM
2007 Equinox - Smog Check Drive Cycle / EGR
