Posted: May 06 2009 at 5:10am | IP Logged

Hello Frontier friends.

I have a problem with my Frontier that I am hoping someone has seen before.

I am trying to avoid going to the dealership to have the code read to save the dollars.   

2002 Nissan Frontier KA24DE engine. 85K miles. When filled with any fuel below 93 octane, engine pings, mileage is poor and service engine light illuminates and stays on. When filled with 93 octane, engine runs ok, but MPG is sporadic (18 to 23) and service engine light comes on at fill up and goes out at about 3/4 to 1/2 tank. Last 1/2 of the tank runs without the service engine light illuminated. I filled last night with 93 and she ran a little rough at 1600-1700 RPM for 50 miles or so and at 7/8th tank the light came on and remains on now at 3/4 tank  It felt slightly choppy when cruising at 50 MPH and ran smoother above 2000 RPM. There was a shift change also when going from 1700 to 2000 RPM.

Thank you for your thoughts,

Charles

Posted: May 06 2009 at 6:20am | IP Logged

Go to AutoZone or any other auto parts store, they will read engine codes for free.  This will likely point you in the right direction of what needs to be replaced.

Keep in mind, when one part fails, sometimes it sends off some false failures to the computer.  For example, my codes read a failed knock sensor and low EGR flow, when the actual problem is just a failed temperature sensor.

A Hanyne's manual will list a number of diagnostic tests to run for various codes, usually only needing a multimeter and a few other basic tools.  Do it yourself, and you'll avoid going to a dealership and spending big $$!

Posted: May 06 2009 at 12:54pm | IP Logged

I will try to get to AutoZone tonight and have the code read.

Thanks for the reply!