Hi All,

Not too long ago I posted a thread where my car got damaged valves due a broken timing belt tensioner, long story short, mechanic give me a cheaper option by buying a used engine and replace it maybe wrong decision but I took it. Now the stupid guy return the car to me with the check engine light on. I complain to him, he got pissed off because I make him sign I document with the crap he did, anyways forget about that clown, I need to fix my CEL

I have checked the codes and got 13, 34 & 51, which according to the list I have is Cylinder head temp sensor, Knock sensor and Fuel Injection circuit open.

Big question is how do I fix them?, before I had the 51 and got it fixed by just pouring a fuel injector cleaner, but back then my car was acting funny, stumble once in a while,weird idle but now runs good it has good power and acceleration.

What can you suggest me to do? any help highly appreciate it. Thanks.

Oh! by the way I have one more problem, not sure if any of this happened to you, my gas pedal when is fully depressed is stuck, I have to put some strenght to get it unstuck and this cause some strong take off which I really don't like to do, do you know the cause of this? could it be just a stuck pedal crank? will some wd40 work under there? sorry for the noob questions, I really don't know what I'm dealing with. Thanks!

Check to make sure that all the connectors to those components are well placed. IMO, that is the only way that those codes kick in.

For the accelerator pedal getting stuck, follow the accelerator cable all the way to the throttle and make sure that there aren't any obstructions to it. Also, it could be that the throttle has enough carbon to stick the throttle. So get a can of throttle body cleaner and try to spray into the throttle. But due to the design of the intake, you may have to take out the throttle and clean it by hand.

Do you know where is the location of the Cylinder head temp sensor for the code 13?

Follow the top radiator hose to the engine and you will see two temperature sensors. The one facing the firewall is the one that triggers code 13 when something is wrong with it.

The knock sensor is the one down below the IACV valve right? or am I confused with the 02 sensor?

The knock sensor is on the firewall side of the block below the exhaust manifold. It will be a little difficult since it's tight in that area.

But could a dirty connector on the top part cause the code 34? before I unplugged that connector i forgot for what reason but that was long time ago, before any engine problems that's why i thought it would be easier but I guess in case I need to replace that knock sensor it won't be easy.

For my code 51 some time ago I had that problem and I was lucky to solve it by just pouring a fuel injector cleaner, not sure if I will run through the same luck, but it won't hurt to try.

For the time being on the knock sensor issue, try the 470-ohm resistor trick (search on the forum) and see if that will clear the code. If not, then it could be a wiring issue.

Are you re-using the injectors from your old engine?

Some things I can think for you to check are the contacts on the injector pins or connectors for corrosion, ohm-check the injectors and pull off the spark plug wire on each cylinder to make sure the engine bogs down.

I'm not sure about the injectors, I think the mechanic didn't put the ones from my old engine. So I hope this ones are not shot.

ohm out all your injectors you could have a open injector coil circuit...noid all the injector plug to ensure power to them...

Sorry I'm not very familiar with measuring ohms on the injectors, I mean I know how to use a multimeter and everything but the question is do I have to remove parts to reach the connectors or this can be done while everything is on place, with car running? just key ON.

Also Today I was driving the Maxima and while driving it I notice shudder and my RPM drop while it was happening, happened 3 times, could this indicate the same problem with injectors probably? has this happened to you?

Just the injector connectors!

Thanks to all! I finally get rid of the CEL, the temp sensor was causing it, a lot of corrosion and broken connector, I clean it and try to secure it the best way I can, check engine went off, problems of car seem to be gone except for the shudder and RPM dropping, but I notice this only happens when the car is cold.

In the morning I start the car and I can even hear on the muffler some popping/sputtering noise and my RPM drops when this happens, once I run the car for a mile or so, car seems to run good, any ideas on this?