P0455 Error Code -1998 Jeep Grand Cherokee
1998 Jeep Grand Cherokee 4.0 L I 6 gas engine 114,000 miles
My 1998 Jeep Grand Cherokee was coughing and sputtering and running very rough but the check engine light was not on. My shop took a look at it (not sure they did a true diagnostic as it was in the shop for a new muffler and tail pipe at the time… a job I will not do myself) and said I needed a new fuel pump. I purchased and installed a fuel pump to the tune of $180 and a lot of labor to pull and reinstall the gas tank. The result was the Jeep still stalls, coughs and backfires.
I think my shop may have misdiagnosed the problem originally and I really did not need a new fuel pump so I took it back to the shop as I was now getting a ‘check engine’ light on. The computer came up with a P0455 error code.
So, with the error code from the computer now reading “EVAP large leak” they did a smoke test and tell me I need to replace the fuel tank filler pipe. This part, if it is in fact the problem, will cost almost another $200. I have a problem understanding how this could cause the kind of problem I have been experiencing. When I pulled the gas tank I did notice the fuel tank filler pipe had a small rust hole in the vapor return pipe. On reinstallation I made sure to clamp the rubber hose above the hole so this should not be the source of the air leak.
Before pulling the fuel tank to replace the fuel pump I had to siphon out more than a half tank of gas out of the tank. I was careful when I siphoned and used a very small diameter siphon tube (less than ¼”) but none-the-less I am thinking I may have damaged something in the fuel tank itself (I know there is a ball stop in there as an anti-rollover device on the fuel fill side and I also experienced some resistence when I put the siphon in the vapor vent hose) and the smoke is coming up from the gas tank and exiting through the filler tube.
Before I go out and spend more money on a miss-diagnosis I would like your opinion. Could something in the gas tank be the source of the problem? Is there any way to check for it (short of taking the tank out again)?
If I replace this part and still have a problem I suppose I could have got a defective replacement fuel pump so I will take the Jeep back to the dealer and ask them to do a pressure test on the fuel pump to see if it is in fact defective. If so, I will return it to the vendor but right now I am thinking I may have installed a new part I really did not need. After going through all the work to put it in I do not plan to take it out again unless it is defective.
I would appreciate any ideas you may have. Thanks again!
Answer - Obviously the problem in the first place did not come from from the fuel pump. The coughing and stalling could be caused by the fuel pump (not necessarily) but the backfiring is a symptom from the ignition system (spark plugs, distributor cap etc.) My advice to you is:
Since you came this far by yourself, try going through it to the end. As you have seen, you gave money and solved nothing. If you do not solve the problem, the mechanic will always be there and you will have to give the money anyway. So, why not try to save a few bucks.
Do the next :
Hope this helps.
Have a nice drive,
carrepairguide.org
My 1998 Jeep Grand Cherokee was coughing and sputtering and running very rough but the check engine light was not on. My shop took a look at it (not sure they did a true diagnostic as it was in the shop for a new muffler and tail pipe at the time… a job I will not do myself) and said I needed a new fuel pump. I purchased and installed a fuel pump to the tune of $180 and a lot of labor to pull and reinstall the gas tank. The result was the Jeep still stalls, coughs and backfires.
I think my shop may have misdiagnosed the problem originally and I really did not need a new fuel pump so I took it back to the shop as I was now getting a ‘check engine’ light on. The computer came up with a P0455 error code.
So, with the error code from the computer now reading “EVAP large leak” they did a smoke test and tell me I need to replace the fuel tank filler pipe. This part, if it is in fact the problem, will cost almost another $200. I have a problem understanding how this could cause the kind of problem I have been experiencing. When I pulled the gas tank I did notice the fuel tank filler pipe had a small rust hole in the vapor return pipe. On reinstallation I made sure to clamp the rubber hose above the hole so this should not be the source of the air leak.
Before pulling the fuel tank to replace the fuel pump I had to siphon out more than a half tank of gas out of the tank. I was careful when I siphoned and used a very small diameter siphon tube (less than ¼”) but none-the-less I am thinking I may have damaged something in the fuel tank itself (I know there is a ball stop in there as an anti-rollover device on the fuel fill side and I also experienced some resistence when I put the siphon in the vapor vent hose) and the smoke is coming up from the gas tank and exiting through the filler tube.
Before I go out and spend more money on a miss-diagnosis I would like your opinion. Could something in the gas tank be the source of the problem? Is there any way to check for it (short of taking the tank out again)?
If I replace this part and still have a problem I suppose I could have got a defective replacement fuel pump so I will take the Jeep back to the dealer and ask them to do a pressure test on the fuel pump to see if it is in fact defective. If so, I will return it to the vendor but right now I am thinking I may have installed a new part I really did not need. After going through all the work to put it in I do not plan to take it out again unless it is defective.
I would appreciate any ideas you may have. Thanks again!
Answer - Obviously the problem in the first place did not come from from the fuel pump. The coughing and stalling could be caused by the fuel pump (not necessarily) but the backfiring is a symptom from the ignition system (spark plugs, distributor cap etc.) My advice to you is:
Since you came this far by yourself, try going through it to the end. As you have seen, you gave money and solved nothing. If you do not solve the problem, the mechanic will always be there and you will have to give the money anyway. So, why not try to save a few bucks.
Do the next :
- Do a double check on your repairs, see if all the lines are put the right way, that all the screws are tightened and check for leaks. Check again on the repair on the vapor return pipe, even if there is the smallest possibility of false air coming in, it will cause a problem. Look again at the filler pipe, the error that the computer shows comes in 95% of cases from a bad filler pipe. I suspect that there might have been some damage done while the installation-re-installation of the tank.
- When you have finished this (making sure that everything is in order) go to the mechanic and check the fuel pressure. This should be free of charge. If it is OK, you have finished with one dilemma.
- After that go and check the ignition system by yourself. Take off the distributor cap and look for any kind of damage (cracks, worn out contacts etc.). Moist under the cap can also cause problems.
Hope this helps.
Have a nice drive,
carrepairguide.org