Just for the heck of it I checked for codes after riding around this weekend up by my cabin. I never got a Check Engine light and it ran perfectly for around 100 miles. I noticed code 41 came up which is for the Air Temp sensor piece of the T-Bap sensor. This code can mean one of two:

Air Temp Sensor: Open or Short Circuit to Sensor voltage (ECU)
Air Temp Sensor: Short circtuit to ground.

I disconnected batter to erase codes. Check and code was gone. I then went for a short ride. Checked codes and it was back. I then disconnected battery and then reseated the T-Bap connector. Reconnected batter and went for short ride. Check for codes and it wasn't there.

I am hoping it was just a bad connection on the T-Bap connector. I am concernered though that it could be electrical. I recently put my winch in and relocated the fuse/braker block slightly up front since I mounted the Warn contactor next to it. Just hoping I didn't pinch anything. It should be easy enough to trace.

What would overall effect of this sensor malfunction causing? Slight loss of performance and worse gas mileage? It would seem coolant temp sensor would play a bigger role than air temp but I could be wrong. Again it seemed to run great this weekend.

I was surprised that CEL didn't come on when there was a stored code.

Treacherous

 

I have that and code 45 on my machine?

What have you descovered to be the cause?

I heard a K/N oil filter will make the sensors malfunction.

I do run a K/N i am curently testing to see if the codes go away with just stock filter..

any help would be great!

 

I posted about this on ATV Frontier as well:

Check out this long thread here:

Thread 1

and this one as well.

Thread 2

 

Hey guys, I posted about getting codes 41 and 43 a while ago also. I found the wires rubbed through and some broken off about 3 inches back from the tbap sensor. They rubbed through against the crankcse breatherhose. I cut the harness off, dissassembled the tbap connector and soldered the connector terminals to the wires before reassembling the connector. I then put plastic wire loom around the harness and sucured it with zip ties. It has been fine for about 200 miles. But strangly last weekend at the end of our ride it didn't want to idle well. It never stalled, but idled rough and at about 750-800 rpm. If I held the throttle open a little it was fine, and seemed to have plenty of power. It was a very dusty ride, and I noticed my K&N filter is pretty dirty, so I've cleaned it and reoiled it. I will go out and check codes, then recheck how it is running.

 

Code 41 & 45 will soon become popular problems. The cause is from the wires on the T-BAP sensor wearing thru the insulation and shorting together or breaking in two. The area to inspect is 2 to 6 inches from the plug. There have also been some cases where the wires are breaking where they enter the plug.

I don't think the K&N or Foam air filters are contaminating the T-BAP sensor. However these filters do allow the air filter oil to enter the throttle body housing and stick to the throttle plate. When this happens a gummy build up forms on the leading edge of the throttle plate and reduces the amount of airflow at idle. This will cause the idle speed to drop and eventually lead to stalling.

The gummy build up can be removed by scrubbing the plate with Throttle Body Spray and a toothbrush. Be sure to clean both sides of the plate and the inside of the housing as well. Once everything is cleaned your idle speed should return to normal.

This condition can occur on both 700 and 800 EFI units. Those who run paper air filters may not have this problem as soon as or as often as those who use oiled air filters.

 

It was a huge mistake to put EFI on an ATV. Nothing good will ever come from this except for making your dealer rich from constant repairs.

 

Had a similar problem on mine. The wires were broken right at the connector. I was unable to get the connector apart. From what I understand the only fix would be to replace the entire engine control harness.
I found metal female connectors that were a close match, crimped them on, reconnected the sensor and secured the wires with tie wraps. Finally, I filled the plug cavity with dielectric grease. 500 hard miles so far with no problems.

 

Well My low idle seemed to be caused by a dirty air filter. I cleaned and reoiled the K&N filter and now it runs and idles normally. Seems the efi models are very sensative to a dirty airfilter... although mine could be worse due to the extra airflow from the sp800 air snorkle and exhaust header pipe. Why didn't I think to check the throttle plate??? It was one of the first things I always did as an auto mechanic when a car came in for stalling or a rough idle. I am going to clean mine and let you all know how dirty it was. As far as the TBap sensor connector goes... I was able to carefullt pry the OE connector terminals apart so I could recrimp the wires to them after cutting them off just after the spot where they were rubbed through. But I also soldered them to be sure of a good connection. If it ever happens again though I'll have to add extra wire to the harness because it will be too short. Oh yeah, I didn't have any codes stored from my rough idle problem. A plug check found my plugs were black, Indicating it was running rich from the plugged filter.

 

I too have had the same problem with broke off wires at the connector like everyone else.. Unfortunately the problem became worse when i lost the paper that I wrote down the wire colors and locations on!

Could someone help me by telling me where each of the four wires go in the plug. On the plug where each wire goes it is labled by slot 1,2,3,4 could someone let me no which wire color goes to which number..

Thanks Like Always

 

I guess no one wants to help out