isuzu trooper fault codes p0401&p1441


Asked by dsimpson1306 Apr 16, 2011 at 10:34 PM about the 1999 Isuzu Trooper 4 Dr S 4WD SUV

Question type: Maintenance & Repair

Hello, I have a 99 Isuzu trooper 3.5l v6. I have to say that I love this vehicle, but since I
bought it 2 months ago it has two codes showing p0401(egr) and p1441(evap). The dealer
replaced the egr valve and evap canister apparently. It was good for a couple of days then
the light came back on. I then replaced the rear muffler as it had a leak. The light then
went straight off. Again two days later it came back on. This thing is messing with me! If
there's any  experts that can help I would really appreciate that. Thank you, dave.

3 Answers

Troy Nadon

try putting a gas cap on it it is one of the most common and cheapest fix for the small evap leak, if the light stays on rec a smoke test at a shop.


The 401 code is the most common code and most often refers to the throttle position sensor( a fancy way of saying gas pedal). I have a 2000 Trooper and I'm assuming yours is also an automatic which means it has an electronic gas pedal. While this makes for really smooth acceleration it makes the check engine light come on needlessly. Now be advised there are other posibilities for the 401 code popping up but the throttle position sensor is the most most likely culprit. You can buy a new one if you want to make it stop lighting up your dash board but mine has been lighting up for more than three years now with no adverse performance. I have my own scanner permanently mounted to my car to monitor fuel mileage and other things and every time I go to check it it's almost always that one stupid code. By the way I hope it didn't cost too much for that new egr valve because they don't go bad, they only need to be taken off and cleaned. If you want to hold on to this vehicle do three things-1 check the oil every week if not sooner ( the early 3.5 l engines have consumption problems) 2 go to and get the factory manual for this vehicle 3 get a code scanner- you can get a scan guage II that sits on the dash like I have and monitors the fuel mileage if you want to save money. If you have any mechanical abilities whatsoever it would be wise to get the factory manual and learn to start working on this thing yourself. Like I said that egr valve code pops up on me every 8 months or so. What do I do, bust out a new gasket and a can of brakecleen. Problem solved and I didn't have to drop $150 on a new egr.


I agree! I have to check my oil on a weekly basis or sooner!! I also clean my egr valve with b12 chemtool and I bought a gasket maker set so I wouldnt have to keep buying gaskets!! Someone had told me that my egr system was clogged up with carb!! I will prob get that checked in a few days but until then I keep doing this process to keep my trooper running on the road! I also had a problem with the airconditioner, but thats a whole new problem.

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