I just had a cng converstion kit installed on my 99 Denali and now my check engine soon light came on. I took it back to the shop that installed the cng kit and they now say that the catalytic converter needs replaced. This is very concerning to me as I had just had the entire vehicle inspected and saftey and I/M done and it passed with flying colors. Could the cng kit cause the catalytic converter to fail?
Tuesday, August 16th, 2011 AT 5:11 PM