What's up guys. I just installed a new header and test pipe I got for cheap off of ebay. Before the install my autometer air/fuel gauge would always flip back and fourth between rich and lean how it's supposed to. Now after the install the gauge reads lean continously after I drive for more than fifteen minutes. Is there anything I can do to correct this? I also have a cel which popped up but I figured it would happend because of the test pipe. Any ideas on what I could do to correct the running lean problem?

Just thought i'd give an update on the problem. I reset my ecu this morning and the cel is gone but the car is still running lean after a few minutes of driving. Any ideas on how to fix this guys??