ecu error codes

[rivetapproved240]

i cleaned my injectors with fuel injector cleaner through the brake booster line. ive done this before and worse case blew an 02 sensor. But after replacing the 02 sensor when the mil light came on it still will not go off. so i pulled out the ECU and got the codes. Codes are as follows; 33- front 02 , 34- knock sensor, 41- intake air temp. sensor, and 12 - mass air flow sensor. attempted to reset ecu and it came back on within2 secs. so in the quest to find all of the above, i found out that 2 of them are dealer items only and 1 is almost $200. so what could of cause all this? i drive a 95 nissan 240sx. checked harness and the all seem fine. thinking about removing the ground and then replacing.

[[s3]]

Interesting method of cleaning injectors, usually I just pour the crap in the gas tank, maybe your method provides better cleaning.

Get a multimeter and OHM check all the sensors, if none are in spec replace them all.

A FSM will help you greatly and I would advise against using that method to clean injectors, if you really want them cleaned thorougly send them to the pros and have them flow tested and cleaned.

[rivetapproved240]

see when you clean your injectors through the break booster line, the car usually stalls out and thats when you stop. well not only did my car stall out, but also was a pain to get it to turn over. and what does a knock sensor do ? i have the 1995 nissan 240sx book i bought from nissan publications for an outrages amount but it sometimes seems lacking. where could i find a air intake temp sensor and a MAF sensor? o an i have aftermarket intake but i have had that on there for a long time with no check engine light. its not homemade it name brand. tried local junk yards for maf and aits, but no luck will any ka24de maf work? how about the same for the air intake temp sensor. i wouldnt mind upgrading to aftermarket maf, but lack of funds is a problem. But Could the 02 sensor cause these sensors not to function properly, i mean i was skimpy and bought a cheap 02 sensor. its Bosch but its the universal one for my car so i had to extend the wire about 3 inch and change out the connecter. i used a tube crimp, shrink tubing, and a regular female connector, and just reused the rubber plug. also dont know if its related, but theres a strange smell coming from the underside of the driver side, smells like hot glue, but its not in the engine compartment. but i did paint my heatshield with high temp paint and some scratch off in the process of putting it back in. i dont know. and suggestions.?

[NISTECH]

clear your codes again. start the car allow the light to come back on and pull the codes again. I seriously doubt all 4 will come back. You have got to be carful with aftermarket intake systems. If you over oil the filters the oil will get on the airflow hot wire and fry it or at least cause it to read incorrectly. I suspect the codes that are immediatly coming right back are the IAT sensor and knock sensor. The knock sensor will not trigger the light only the IAT will. If you have the maf code immediatly it is either contaminated with oil or has a poor ground circuit adding an additional ground to it can help resolve that. If the O2 comes right back on you need to check your work carfully. A graph meter would be extreamly helpful in diagnosing that.

When you feed the cleaner through the brake booster line you are not cleaning the injectors you are doing a partial cleaning of the intake manifold. The only proper way to clean an injector is as mentioned above or with an inline feeder the hooks up to the the fuel line between the filter and the injector rail. That equippent is usually only available at a shop as it is usually leased to the shop by a company that makes the cleaner.

[rivetapproved240]

checked into it further, checked fhm also, my maf couldnt be blown due to i can rev past 2400 rpms. my intake temp sensor was a little loose. i took it off blew out the connections and put it back in. 02 im not even gonna bother with, i am going to buy one from nissan. but my question still is what does a knock sensor do?

[rivetapproved240]

o and i havent oiled my intake lately

[[s3]]

knock sensor detects knocking in the engine, like when you use crappy gas or engine is running out of spec.

It will trigger a code 34 when the sensor itself is out of spec/missing/broken

Replace it or else the car will run in limp mode, usually with all Nissans that I've worked on they will run in limp mode if that sensor is damaged.

[rivetapproved240]

see it isnt running in "limp mode". it feels as if i have more throttle response than prior. also for some strange reason my brakes dont grind and i stop more easily. i wonder if the 02 sensor is just shot and causing everything else to be funny. also the knock sensor could it be that when i put the injector cleaner in the break booster line it picked it up when it hit the cylinder and caused it to trip? and it could just go back off adventually? and how often shoild i oil my intake filter?

[[s3]]

Probably your imagination, I doubt your car is running "better" with a bad knock sensor.

Most Nissan cars have a fail-safe set of fuel maps that they run when they encounter problems like a bad knock sensor, or if the sensor is detecting knock. The ECU will switch to this fail-safe limp mode until the problem has been resolved. This prevents the engine from grenading itself.

Reset your ECU and run the car again, then check once more for codes if they come back, fix the sensors.

Oil intake very 6 months or when it gets clogged up and dirty.

[rivetapproved240]

alright took intake off, reconected everything, and c leaned connections,as before mention intake air temp sensor loose, tightened, reconnected everything, made sure all hoses where connected and no leaks where seen or heard, drove car to work, pulled codes today, reset ecu and got code 55- all clear, i think my car has a sense of humor.