1993 Lincoln Town Car won't run at idle
Was pulling 172 & 176 codes. After pursuing the common stuff I decided to pull the elbow to check the plenum. Put it back together and now won't idle. Smoke tested okay and no unplugged connectors. Before this I had good fuel pressure, new fuel filter, New O2 sensors, spark plugs IAT, and cleaned MAF. It starts okay and if I gun it some get backfire from exhaust pipes. Run it for awhile and no codes come up with my Innova tester. Can't figure what I screwed up. EGR valve motor/valve or DPFE?