1991 Camaro RS 3.1 V6 AT. 190,000 miles running strong as ever... can still smoke the tire to oblivion... rumbles along with flowmasters. few hundred miles later...damn. The engine decides to max-out at 36-4000 RPM. Horrible gas mileage. gets about 10mi/gallon! used to get a good 15,16. Running really rich. When 100% throttle, engine fluctuates between 36-4000 rpm and just surges. In idle and in drive. Takes a good hill to hit 70mph. Heard i may have a bad PROM, decided to pull one from a junked Firebird so i dont waste money on a brand new chip in case that was the problem. 'bird's chip in...nothing. May be a bad ECM, swapped with the 'bird's... nothing. Changed 02 Sensor to try to pass smog, no luck, changed Coolant Temperature Sensor (activates ECM) no luck. ECM was remaining in open loop for a looong time. even at and beyond operating temp. Thought it was a clogged Cat. pulled exhaust manifolds.... nothing. was clogged but problem still existed. Had a bad injector. replaced, made little difference. Last week driving along on the freeway slow down for traffic. traffic moves, give it gas, hear a tapping in through the exhaust from the engine. pull over, check under the hood, hear a tapping from the valve cover. think its a loose rocker arm. WHAT ELSE CAN WRONG WITH THIS F'IN CAR! Starting not to care since I've got a 350 waiting to take over for this sucky tired 6 cylinder, thats taking up space in a nice third gen f-body. Anyone ever have this problem... Can anyone help?