A car fails I/M with high NOx. EGR valve is commanded open, but MAP readings show no change. Fuel trims are balanced. What is the most likely cause?
Our free L1 practice questions act as a diagnostic tool to give you a clear snapshot of your Automotive Service Excellence Level 1 readiness. Discover which topics are your strengths and, more importantly, which critical topics require your immediate attention.
| Name | Automotive Service Excellence Level 1 |
| Code | L1 |
| Vendor | Skilled Trades |
| Certification | ASE |