Codes 21 and 41 (1 Viewer)

[Icicle]

Truck has been running great.

Yesterday on my way hone from work, MIL lamp came on at the kids daycare, and idle was weird, high and then back to normal.

On my way to work this morning (20 miles, mixed driving) it ran like a top, until right before i got there, light came on. Truck runnning great and idling smooth as butter during this occurence

On my way hone tonight, light came on in the exact same spot of my commute it did yesterday, but this time there was no idle issue, 625 rpm and smooth, ran great.

O2 sensors are 2 weeks old. No light until yesterday. Connections are tight, dry, and clean.

My tps is 6 months old, brand new toyota one.

Im puzzled. Ideas?

 

[Warpigg]

Is the tps adjusted correctly? Did you test the o2 sensors for faults?

 

[Icicle]

Is the tps adjusted correctly? Did you test the o2 sensors for faults?

The TPS was adjusted correctly 6 months ago, and no I havent checked O2 sensors yet, they're brand new and worked fine for 2 weeks.

I'm more concerned that I get both of these lights at the same time out of the blue for no apparent reason, and why.

Are codes 21 and 41 both codes that will trip the light, or just the o2 code?

Do all codes trip the light on an OBDI vehicle, unlike OBDII?

 

[Warpigg]

All codes trip the light on obd1 and 2. The tps may have come loose or failed in that time and the o2 sensors may have failed in that time. It's throwing the code for a reason. Start with checking the items that the code is sourced from(tps and o2 sensor). Then go from there.

 

[Rifleman]

I havent checked O2 sensors yet, they're brand new and worked fine for 2 weeks.

Hate to tell you this, but just because they were working right 2 weeks ago, and were "brand new" doesn't mean they can't fail, although it's not likely, it can happen. When you replaced the O2 sensors, did you use aftermarket or factory sensors?

The reason i ask, there has been more than one thread here on Mud, were other members have reported problems with aftermarket O2 sensors. If you do find out that the sensors are bad, and you want to try factory one's, Toyota has a replacement program where you get 2 new sensors, along with new nuts, and gaskets for about 240 bucks. Here's a few links for you to check out.

How i fixed my 94 L.C. check engine light Code 26

http://www.risingsun4x4club.org/upl...r manual/Service bulletin/T-CP-SO2-0162-W.pdf

 

[Thecriscokid]

Hey gang, just thought I would share my code 41 issue.
I’m behind the wheel of a 94 and picked up 28 and 41 codes after my recent 3000 mile trip at lower altitudes than my normal 8-11,000ft routine driving.
Code 28-running rich can often be the motor choking, so I cleaned the air filter until I get a new one, code vanished.
Code 41-throttle position sensor, engine bumbling at low rpm etc. I tried all the norm-checked vacuum hoses, connections, checked wiring for abrasions, reset the ecu a few times, scratched my head a bit. Sometimes extreme change in climate can cause tubing to become loose fitting. Tried these things when it was warm outside (65) cold outside(35) engine hot, engine cold.
The throttle position sensor is obviously in question so what does it do? Simply tells the ecu where the throttle is positioned. It is just a simple switch that turns when the throttle is pulled. I messed around with my hand throttle, locking it slightly pulled. It ran better but not ideal. The tps has an adjustment range so I tried adjusting one way(without hand throttle) , ran poor. Adjusted the opposite way and it ran fine but then would die at a stop. Through all this the pedal had some lag time, very slow to activate the throttle.
Hmm, what are the chances that over the last 25 years and 260,000 miles that the braided cable simply stretched? It’s just an oversized shifter cable for a bicycle... bicycle shifting is adjusted by 1/2 milimerers to find the sweet spot...next I adjusted the throttle cable and positioned the tps to match. I made a few minuscule adjustments and found a sweet spot. I don’t know if this is a permanent adjustment and only time will tell. Today I ran some extra long errands and put 100 miles on my adjustments and the girl just purred along. No bumbling or complaining of any sort. If this adjustment doesn’t last I will report back. If nothing else this will get you out of the woods and back to grandmas house. I have a replacement tps sensor, wires and plug en route but I will continue to drive with my existing knowing that I have a replacement in the cubby within reach. Cheers