Pontiac Repair: 96 Pontiac Bonneville shaking

Question
Hello Todd,
Today my 96 Bonneville started shaking and trembling when I was at a red light. I also noticed the CEL flashed for a bit and then stayed on. The CEL has been on for quite some time and I just haven't been able to fix it. I checked the scanner and it read the code P0171. I didn't want it to turn off on me so I just took it back home. I checked a couple hours later and it still starts but I am worried I will mess it up if I keep driving it. Would a tune up fix this? Any inputs would be greatly appreciated. Thanks!

Answer
Hi Anthony:
well if the CEL is flashing the engine is misfiring. those engines were noted for ignition system issues spark plug and wires were issues if it's an intemittant misfire it could be one of those if it's a constant misfire then it may be more major like a coil or an ignition module. the po171 is a lean code. it can be cause by a vacuum leak from a split vacuum hose. it it had a tuen up recently or an oil change and the PCV valve was replaced it could be the wrong one or someone forgot to replace the -ring that goes on the vlave very common mistake on that engine. the 171 could be cause by a plugged/restricted fuel filter. when was that replaced last? usually that is the last thing to get replaced after people throw every part under the sun at one of these. that is just a few ideas with out seeing it I can't tell you for sure what the issue is these are just gueeses but they are very common issues on those cars. good luck :-)