Hi Guys, pretty new to the forums here and couldn't find anything related to my issue. I have a bone stock 95 XR7 cougar that was throwing the P1407 code. I have emissions testing coming up soon so I decided to attack the problem by throwing a new DPFE sensor on the car and driving off happily into the sunset. Well upon test driving the car I noticed the idle was now very rough and I can hear an intermittent knock on the passenger bank. At first I thought I had installed the intake elbow incorrectly and caused a vacuum leak. Re-installing the elbow after a good sanding and new gasket did not solve the problem, only during this test run I happen to notice the ignition advance is at 22 degrees just idling in park on the driveway. I thought perhaps the cam position sensor was bad, unplugging that did nothing. The IAC seems fine because unplugging that also changed nothing. Re-installing the old DPFE sensor made no change either so my thoughts now are that a bad timing chain guide is causing the cam to rotate out of time, but I didn't want to tear that far into this without hearing out some other possibilities. Please advise, thanks Y'all!