Code 25 and 26, any thoughts? (1 Viewer)

[109madrid]

I recently replaced my TPS sensor and rear knock sensor to clear the CEL light on my 1994 Land Cruiser. It cleared the CEL lights for a few days, it's not my daily driver so it doesn't get driven more than once a week yet so it's not cycled much. After changing the TPS, the idle was high (over 1200 RPM's) while in park/neutral but when in gear it idles great (around 900 RPM's). After a few days running with the high idle, it is now throwing both code 25 and 26. I do have a small coolant leak but that's all I can think of for throwing both lean/rich codes.

 

[109madrid]

Here's the coolant leak and I am waiting for the orings to fix it...

 

[ajax1]

Those are o2 bank codes , fsm lays out how to check or roll the dice and buy o2 sensors but could be the wiring

 

[93yotasr5]

Most likely O2 sensors. I've gone round and round with all the other possibilities and it always came back to the O2 sensors. Do yourself a favor and get the Denso sensors.

 

[half k cruiser]

I agree with @93yotasr5 about checking the wiring down by the connectors first. Sometimes they get brittle, and are in a pretty vulnerable location to get taken out by debris. You will be wasting time and money buying anything other than the OEM sensors. I tried going the cheap route on my 94 but that didn't work out. I ended up spending more money. Do yourself a favor and order the OEM ones at the best discount you can. Also, while you can buy the regular Denso from amazon for the 95-97 trucks, I don't think the 93-94 are a Denso sensor. There is another brand, I think NPK, that does these sensors. @beno will know.

 

[Kernal]

Could be your Oxygen Sensors, or the wiring at the O2 sensors; you could check the wiring to see if it's melted or shorting out anywhere, check the connectors to see if they're corroded internally (disconnect, clean, reconnect). And then check which brand sensor they are; if they are Bosch aftermarket, you should change them. RockAuto has good prices on NGK and Denso sensors.