Quote Originally Posted by apierce1289 View Post
Mine is always at 14.7 no cat.
What is 14.7? The Air/Fuel ratio reading on the data scan from the PCM? That may not be a number you can trust. You either need to watch the narrow band O2 sensor voltage and fuel trims or install a wideband O2 to determine what is really going on. I guarantee you if the scan data says the engine is running at 14.7:1 AFR, it isn't actually doing exactly that. Hook up a wideband O2 and you'll understand what I mean. The "14.7:1" value displayed in a data scan is just the "desired" or "calculated" AFR the PCM is trying to attain. That isn't what is actually going out the tailpipe, I can assure you.