James909
Well-Known Member
- Joined
- January 17, 2008
- Messages
- 674
- Reaction score
- 3
- City, State
- Long Island, NY
- Year, Model & Trim Level
- 1994 GMC Yukon 2 Door
Hey guys. I'm helping my dad fix his '97 Mercury Sable (3.0L DOHC engine) but we're both kind of stumped. The CEL is on and when I pulled the codes they were P0171 (Bank 1 Lean), P0174 (Bank 2 Lean), and P0300 (Random misfire). The car is hard to start and when idling for a couple of minutes will stumble and sometimes stall. This was happening before the CEL came on though so I'm not sure they're related. Also initially the car was showing a P1409 (EGR vacuum regulator malfunction) but went away after the vacuum regulator was replaced. We both thought there must be a vacuum leak but we couldn't find one. Are there any spots on the engine that are prone to vacuum leaks? Any other ideas on what would cause these codes? The car has 215K miles on it and I think the fuel pump is going. Could a bad fuel pump cause these codes? A fuel pressure test is next on the list. Thanks in advance.
