Gas Recirculation Valve (egr Valve) problems of the 2020 GMC Sierra 1500

1. On 05/9/25, the exhaust emissions system malfunctioned, triggering diagnostic trouble code p2c7a (exhaust emissions system failure). This repair, the seventh attempt since June 2024, addressed the same recurring emissions issue previously involving replacements of components such as the nox converter (02/18/25, 03/13/24) and egr valve (02/18/25). The vehicle is available for inspection upon request. 2. The p2c7a failure risks limp mode, reducing vehicle power unexpectedly, which is hazardous on highways, especially while towing. Exhaust emissions system malfunctions release excessive pollutants, posing environmental and health risks to others. 3. Yes, the p2c7a code was confirmed by dealer during the 05/9/25 repair, following prior confirmations (e. G. , 03/31/25–04/05/25. 4. The vehicle was inspected by young Chevrolet-Cadillac during multiple repairs (e. G. , 03/31/25, 05/9/25). 5. Yes, the check engine light and onstar emissions alerts appeared prior to the 05/9/25 repair, first noted ~June 2024 (p2c7a onset). Exhaust smell and reduced fuel economy were observed intermittently. Symptoms persisted post-03/31/25 repair, leading to the 05/23/25 service.

Engine light would come on for a few days and than turn itself off. This occurred for about 8/9 months; however, instructed by the gm maintenance department that if the vehicle came in and the light turned off before they got to it I would be charged for the diagnosis and no work would be performed. Engine light came on and I was able to park the vehicle / they picked it up and read it prior to putting in their lot until a tech became available. Gm maintenance was able to diagnosis that there was an issue with the egr sensor and nox catalytic converter without filter failed / both items replaced.

I had engine failure in June 2024 with roughly 50,000 miles. I was getting on i75 north in auburn hills, mi, when I heard a loud pop. The vehicle began shaking violently with a loss of engine power warning displayed, loss of oil pressure displayed followed by 2 successive limp mode warning. The vehicle would not drive over 25 mph. Luckily the next exit was only a mile down the road. I was able to drive on the shoulder of the interstate to get off of the highway. When I parked the vehicle shortly after, I viewed oil spewed all over the engine bay and under the truck. I then waited 4 hours in 95+ heat for a tow truck. The engine was replaced by the dealer with no root cause identified or communicated to me. There were no warning prior to this failure. The vehicle has had over 13 warranty related issues including the def heater melting, cac pump failure, numerous exhaust leaks, nox and egr sensors failing, brake control module faults etc.

At about 3500 miles lifters on two cylinders colasped. Took to dealer that dealer had three weeks but fixed it. 1500 miles later at 5036 miles it happened again on a different cylinder. Number 8. The first time it was 3 and 5. The first time the dealer replaced all 8 cylinders. So cylinder number 8 was new as well. GMC has said there is nothing else that can be done to fix the issue. The second dealer service manager states that he would not trust it either to go any long distance . Also stated that they have put 3 sets in to one vehicle before. As an ase master certified technician I find this disturbing. I also was a GMC,pontiac, Oldsmobile master technician. This is unexceptable for gm to think this is ok to take people's hard earn money and not fix there issues or make it right. I owned a 2014,2016,2018 silverado's that had no issues what so ever. To make things worst GMC road side assistance forgot about the truck broke down in 7 degree weather with 35 mile an hour winds. For over 24 hours and several calls back to finally get a supervisor to speak to. Two dealers say that it is unacceptable except the current dealer that is dealing directly with GMC. Anyone can do a search on gm truck lifters collapsing and you immediately overwhelmed with info. It is also disturbing that a dealership service manager says we could put a new engine in and the same thing could happen. That to me is poor quality control and poor customer service. I have always been a gm enthusiasts but this will be my last one. Horrible customer service and do not build a good product or stand behind it. Gm should be ashamed of there fall from grace. This all happened just driving once to work and once hauling a atv on a trailer.