Check Engine Light Due to Gas Cap or Catalytic Converter on Pontiac GTO

Problem Description and Possible Solution

A loose or worn gas cap or a faulty catalytic converter are two common items which can cause Check Engine Light to illuminate.

Problem Data
RepairPal Verified
Average mileage: 106,213 (106,213–106,213)
3 model years affected: 2004, 2005, 2006
4 people reported this problem
Viewing 1 - 1 of 1 problem details
Check engine light came on a few days ago. Got it checked and there was an error for catalyst efficiency below normal.