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Check engine light and thumping noise related?


Topic starter

2000 Lincoln LS with 115000 miles. Check engine codes are P0171 and P0174. I have replaced PCV valve hose and EGR valve. Recent tune up but dont know if all gaskets were replaced. Did have oil in chambers before tune up. Check engine light still on. Was turning off when placed in park (not drive or neutral) but not now after these repairs.

It also makes a thumping noise when taken on highway and going uphill. Doesn't seem to lose power. Braking is rough too. Brakes and rotors recently done month ago and told tires are good. Suspension work done year ago.

1 Answer

Well it's running lean and there are a million things that can do that from a clogged fuel filter. Weak fuel pump worn fuel injectors. Bad math sensor. Computer failure. Tons of things. So I'd start by pressure test and the fuel system see if it's just a worn out fuel pump