I have a 00' 3.4 which keeps throwing this code. Replaced this sensor and check engine light came back on 20 minutes later. There is a pinging noise in the engine when under load. I'm thinking there is a air leak somewhere causing it to run lean. Or another sensor going bad causing the engine to run lean which would throw this code cause the sensor couldn't compensate for the problem<IMG src=smileys/smiley5.gif border="0">Any suggestions would help, I'm stumped<IMG src=smileys/smiley7.gif border="0"> Would like to condsider all possabilities before replacing intake gasket.<edited><editID>jedinpa</editID><editDate>38551.8824652778</editDate></edited>

 

is the CAT new, or newer?

 

CAT is still stock. It has never been replaced.

 

I have the same problem with the o2 code, what did you find out that it is, have replaced the o2 sensor, fuel filter, spark plugs, cleaned mass air flow sensor and thinking about the TPS next

 

i have seen issues where the O2 sensors are repeatedly going bad because of problems with the CAT...not on this particular vehicle, but in general. do you have unusually high mileage?

 

No, not for a toyota. Only 93,000. It maybe that my mass air flow sensor is bad b/c I've already cleaned it. ???????

 

The problem is when I push the throttle down quickly there's a hesitation. If I put it to the floor theres an even longer hesitation.<IMG src=smileys/smiley6.gif border="0"></P>

 

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Only 73,000 miles young, can't imagine cat is plugged but I'll pull it off and have a look.</P>

 

<IMG src=smileys/smiley1.gif border="0"> FIXED !!! It ended up being a bad gasket where I had replaced the O2 sensor !

 

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Thats great you got it fixed!<IMG src=smileys/smiley4.gif border="0"> Were you having any pinging noise in engine when accellerating? Truck goes to dealer on monday to see if they can figure it out<IMG src=smileys/smiley5.gif border="0"></P>


Heres the crazy part, the same day I scheduled the appt., the cellight went out on its ownbut pinging in engine is still there.</P>