Before we tested our Warpspeed Y pipe vs the Cattman Y pipe we made sure we had a clean air filter and pulled the front 3 spark plugs to make sure they were in good condition. We wish we had pulled them all.

We were determined to find what was causing the high speed miss we found with both Y pipes during the dyno tests.

We took the Max into Dan's Nissan dealer and the service department found the rear 3 spark plugs had almost burnt completely off. They ran test after test but could find nothing wrong to cause it. We showed them a photo of the cattman Y pipe before we knocked out the dent prior to the dyno tests. They said they felt because of the dent in the front pipe it caused the computer to run the back 3 cylinders leaner because of the skewed readings at the o2 sensor. Dan had run the dented pipe for a couple of months and the plugs only had 8-10,000 miles on them. We brought it back in for exhaust manifold temperature readings to make certain the engine was running properly with the new plugs and our Y pipe which were normal.

So if you have a bad dent or any dent it might pay to check your plugs. The service manager said Dan was lucky nothing from the plugs ended up in a cylinder. At least we now know why it was running so poorly during the dyno tests.

Dallas Warpspeedperformance