A few weeks ago my engine light came on in my 95 Max. I went to the ECU and checked the codes, the rang up as 0304 and 0303, the front left 02 sensor and the knock sensor. Rather annoyed I would have to replace these, I ran gas cleaner and premium gas for a tank to see if it would help. I was noticing no problems with the car whatsoever. About a week later, I get the telltale signs of the thermostat broken. (engine overheating and cold air from the heater). I went and fixed the thermostat for $15, and then for the hell of it reset me ECU to see if the problems were different. Tada! The engine light turned off!

Not sure what to learn from this, but just thought I'd share the solution to my more expensive problem...

 

...the codes might come back.

 

they'll most definately come back. i reset my o2 sensor cel every few weeks/months. (will eventually replace it with one from www.oxygensensors.com )

btw, what grade gas do you USUALLY run? should be running premium always...

 

I know I should be... but I honestly didnt notice i was supposed to run Premium until about 1 year in to owning it, and never had any problems at all. I ran a few tanks of premium and didnt notice a change in mileage or performance.

Hoping it doesnt come back...

 

It'll be back... I promise

 

how's thermostat affect o2 and knock? I replaced my thermostat for the heck of it a few days ago.
Jae

 

That dreaded little yellow light.

 

after resetting the ecu, the ecu has to run its cycle before returning (200 miles).

 

Mdeezy, your saying the ECU wont redetect a problem till it has run through 200miles of data?

 

yes if you have a malfunction after reseting the ecu it has to run its test before it thorws the cel back, sometimes it will throw the light after a day of driving but usually a few days of driving are needed before a cel will come back.

 

200 miles? didn't see that in the FSM. Maybe I missed it. Can you tell me your reference?
Jae

 

A Certified Nissan Tech. (not at a dealership, he (they) have their own independant shop.)

 

How long and hard was the thermostat to change? I'm not really afraid to do it, it's just that it's been fricken cold out lately and not having heat in the car sucks. But not having a garage to work on your car is just as bad.

Anyone know how much this cost if I get it changed somewhere?

 

took me about 30 mins, with radiator drain and flush. it doesnt take long as long as u haev the right tools to speed up the process.

I had an air ratchet an that l shape ratchet attachment thing, it can bend at a 90 degree angle, without that I would still haev a cell and bad thermo code.



it must be cold up there, its about 39 down here, and I dont want to work on the car cause my hands will freeze up quickly, ifyour colder than that, plus dont have a garage!! damn maybe wear thick *** gloves, or a shop should cost more than $130 to do, but thats still a rip in my opinion cause you could do it for the cost of just parts (around $25)

 

Replacing the thermo is not a problem at all. Ive never worked internally on my car, and just decided I could do it. I read up and bought a repair manual for my max. About 20minutes to figure out what I was doing, and about 30 to do it.

BTW, if you dont flush the radiator, it pretty much flushes itself the second you pop that hose off. I lost about 1/2 gal before i got a plug on I had ready for it.

I loosened one of the belts, to get easier access to one screw, and then its just a pain to try to reach the three screws, but nothing you cant handle.

Keep in mind I have a '95, and ease over the years may change.

 

If coolant comes gushing out, don't forget to rinse all the coolant out of the engine bay.

I used a open ended wrench, deep socket and ratchet to get the thermostat off. didn't touch any belts or tensioners.

Jae

 

Thanks for the help guys. It was finally over freezing on Saturday so I broke out the tools and sucked up the cold for a little while. Drained the coolant and replaced the thermostat in about 40 minutes from start to finish (including clean up). Really easy and anyone scared to tackle it shouldn't worry.

It's so nice to have heat back