Mr. Robinson drove his vehicle around for days with his check engine on when he finally decided to schedule an appointment. At the shop, the technician checked the PCM with his scan tool to confirm the code that was causing the check engine light to be on. It was discovered that Mr. Robinson’s car had a P0171 System Too Lean (Bank 1) stored in memory.
The technician then began his standard inspection procedures. He started with a visual inspection of the intake system and vacuum hoses, looking for anything loose or broken; he could not find anything. The engine idle was normal and did not fluctuate.
He then proceeded to hook the vehicle up to the exhaust gas analyzer to monitor all gases, paying particular attention to the CO2 and O2 readings. He was able to see that the O2 readings were elevated suggesting that there was an air leak. He then proceeded to raise the vehicle on the lift with the engine running so he could inspect for exhaust leaks. Again, he found nothing. The technician then viewed the PID’s for the long term and short term fuel term corrections and noticed that the short term fuel trim was adjusting upward, evidently due to an increase of oxygen.
With the vehicle running the technician used a water and soap mixture to spray suspected areas in hopes to hear the idle change signaling a leak, he had to such luck. The diagnostics that were preformed took 3 hours and they still didn’t have an answer. Mr Robinson left the shop with same problem that he arrived with.
There is technology on the market that would have saved this workshop time and achieved the results needed to fix Mr. Robinsons car, leaving the customer happy and the workshop profitable. Diagnostic Smoke® vapor machines equipped with OEM Approved UltraTraceUV® dye give technicians a fast and effective way to find leaks that other methods cannot.
The smoke machine pictured below was used by a different shop diagnosing the P0171. In only a few minutes they were able to find a leak in the weld around the threads that held the O2 sensor causing the P0171. Smoke Technology utilizing UltraTraceUV dye is truly the most efficient and fastest way to find leaks and other needed repairs, and retain your customers!