Check engine Light and no Catalytic converter. Air fuel ratio?

Just wondering what is going on with my timing and air fuel ratio etc now that my catalytic converter is no longer in my truck. Should I just get the URD 02 sensor fooler gimmick?

My catalytic converter fell apart at 130,235 kms. Warranty was good till 130,000 kms. Dealer would not do "goodwill" And no way in hell I am giving Toyota $1,800 bucks for a new cat!

 

It's probably running in open loop if you have a CEL. In closed loop, the ECM is controlling the A/F ratio using inputs from the O2 sensors and the MAF/intake air temp sensor, so the A/F ratio is constantly being maintained at ideal relative to the environment. In open loop, it defaults to a preset A/F ratio that is probably a little rich in order to protect the engine. So your gas mileage and power output are probably suffering. Not sure what the long term negative effects are of running in open loop and without a cat (besides polluting the air), probably none at all. Not sure about the O2 fooler, I have no idea what it does exactly relative to affecting A/F ratio and timing.

 

Magnaflow has good replacements for around $275 or go with a California grade Walker cat or CatCo. I'm guessing all tacomas require California grade cats no matter what engine?

 

I did a bunch of looking around the net, and did not see any 5 dollar radio shack resistor mods for a second gen, so I just ordered the URD o2 sensor bypass.

On a side note, I noticed about 2 mpg increase with the contents of my cat missing. I have tracked every tank of fuel in my truck since I bought it new. But I think my cat was falling apart and plugged for a couple of months!

 

good idea with the 02 sim

 

I'm trying to figure out why the cat died. If the truck was running properly with no CEL, they cat would be fine.

Something was causing the engine to run in open loop before the cat got bad. Sending excess unburnt fuel into the cat what kills them.

Soooo, can you honestly tell us the truck did not have a CEL before the cat failed?

We are all friends here and want to learn, you can be honest.

Later

KO

 

Nope. Check engine light for like maybe a day. The failure came on real quick. The part that I noticed anyways. My only indication I had a problem was my truck got low on power, and had a bad exhaust leak right off the manifold, where the exhaust pipe meets up. I use my truck exclusively for work on rough gravel and muddy roads. Like washboard rough in spots. I think the catalytic converter failed from vibrations. Like turned to powder and plugged up. 1st pic is some of the powder from the cat when I was trying to figure out why my exhaust doughnut was blown out.

 

Looks like the cat overheated? An exhaust leak might cause the O2 sensors to falsely read a lean condition and cause the ECM to richen the mixture. After a while the excess unburned fuel could cause the cat to overheat and eventually disintegrate. Not sure about this, just hypothesizing.

 

bad idea unless you just want to turn off the light see gadgets site URD
http://urdusa.com/Electronics-Rear-....html?osCsid=49dfcbdb246f56bf345bc41ffb2669f4
and (kevin sullivans auto 101) http://www.autoshop101.com/autoshop15.html You will thank me or curse me

the sim works with a properly functioning sensor............ at best it will only not show the cel/mil it won't do anything to take you out of default stoimetric 14.7:1 af ratio. which isnt always a bad thing however their are other things involved........If you want to learn about these things yourself

the the best place is kevin sullivans auto 101 (toyota based) it might be automotivetraining 101.com either way you will find it


left hand side / tech articles pan down past the hybrid stuff till you see the obd section then a mod should ad it somewhere ............. Everyone should check it out....... I have been reading it for years . Im sure even kevin himself refers to the information ( the instructor)

veteran of the old delphi Days tora t tora t tora

 

Thanks for that link, Scoots. Unbelievable amount of info. Anyone who wants to know how the engine and ECU(s) and BCM's work will find this very usefull.

It is now bookmarked.

Thanks

KO