It takes a good 4-5 secs to start some times while other it’s instant. My gas mileage is horrible... I have changed fuel injectors, spark plugs, coil packs. Have also been putting seafoam into it. Also a very strong gas smell is coming from my exhaust. I don’t really know what else there is to fix this problem that has been ongoing for 3 weeks now...

  • Have you already tried an OBD reader for diagnosis? It sounds like the engine is running very rich, it could be a limp mode because of a faulty sensor (crank, temperature, oxygen, MAF, etc).
    – MadMarky
    Commented Apr 13, 2018 at 7:22
  • Could be a broken head gasket or piston rings and car is now burning oil. Black smoke normally indicates burning oil.
    – Daniel
    Commented Apr 13, 2018 at 8:27
  • 1
    @Daniel - Actually, black smoke indicates a fueling issue. Blue smoke would be oil. White smoke would be coolant. I really doubt this has anything to do with a head gasket or rings. Commented Apr 13, 2018 at 10:47
  • Sounds like the fuel pump controller has failed and put the fuel pressure to the maximum. Read your OBDII codes! Fuel pump relays are common to fail those years, since they are in integral part of the fuse box, i have seen people wire around them and hotwire the fuel pump, which causes your exact issue.
    – Moab
    Commented Apr 13, 2018 at 13:17
  • 1
    What’s the eighth character of the vin? Codes? Fuel trims? Have you done a power balance test?
    – Ben
    Commented Apr 13, 2018 at 19:49

3 Answers 3


It sounds like your engine is getting an alternate source of fuel somewhere, too much fuel pressure, or a mis-reporting sensor such as the coolant temperature, or mass air flow.

As @moab has kindly pointed out, your vehicle does not have a fuel pressure regulator on the injector rail as the slightly older models did, so that can be eliminated as suspect in your case.

A fuel pressure/leak down test should be performed, as well as a system scan of all sensor values, and modules for any other manufacturer specific module codes that might not show up on a generic OBDII scan. These tests should shed some light on where to look next.

  • Your suggestion of a ruptured pressure regulator diaphragm is a good one. Commented Apr 13, 2018 at 10:53
  • Too bad that model does no use a FPR.
    – Moab
    Commented Apr 13, 2018 at 13:03

your description sounds like o2 sensors..un plug positive battery cable replace both o2 sensors let set for about 30 minutes reconnect battery cable start engine..when replacing the o2 sensors use a good brand like bosch

  • Could you elaborate on this - for example, how could the asker test his O2 sensors to see which, if either, have failed, rather than simply blindly replacing both?
    – Nick C
    Commented Apr 16, 2018 at 8:47

You mentioned replacing coil packs & spark plugs did you forget to mention plug wires or didn’t you replace them , if not quite possibly there’s your problem . Otherwise regulator diagram good choice and easy fix.

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