Search of the internet turned up two possible causes for P1126 - one is for a bad or leaking thermostat and the other a defective relay. Has anyone had this code and what did they replace to fix it? Thanks in advance.

I also read during the search that the Maxima has 2 thermostats - one a generic replacement and one a dealer only replacement. Never heard of something like this before.

 

What year is your car? I'm assuming 00-01. The codes aren't interchangeable between years. For a 00-01 it's a t-stat, and for 02-03, it's a throttle relay.

If it's an 00-01, then get a new t-stat. Dealer / Autozone / etc, cheap part, fairly easy to install. Follow the coolant hose from the radiator on the right side (pass) of the engine, on top of the idler pulley you use to adjust the belt tension.

 

According to past posts, he has a 5th gen.

As NmexMax said, replace the main thermostat, see if that fixes the problem.

Yes, the DE-K has two thermostats, same style as the VQ35 Pathfinders (decent actual pics can be seen here: http://www.z1motorsports.com/350_g35...6deqj0nrft2oj1 )

 

Thanks, and yes it's a 2000 Max.