P0133 help

Joined
Feb 8, 2007
Messages
101
Location
Friendswood, TX
Well, for starters, I have a 96 80 with 186K on it. I recently had a check engine light thrown with a miss/hesitation, after scan it turned up two codes, a P0305 and a P0420. I started by hunting down the misfire on #5 and found the harness to the injectors resting reather hottly on the EGR supply pipe. I am pretty sure I remedied that ill, involving unwrapping the harness, and taping the gimpy insulated wires, and re-wrapping the harness with high temp header wrap as well as part of the EGR tube closest to the harness. It started up smoothly and idled well too. I took it out for a test drive and the miss came back, but it was a little different. It appears at partial throttle, but clears up at WOT. I got another code today, it is a P0133 (heated O2 sensor).

My question is, is this a common behavior for a P0133, or could it have something to do with a heated wiring harness? I have no idea how old the O2 sensors are, and I guess I should replace them. Has anyone else had this issue?

Matt
 

619TOY

 
Joined
Jun 27, 2006
Messages
1,820
Location
San Diego
My rig has thrown the same code as well as PO130 in the past few weeks. I clear the codes when they come up with my Scangauge but I just bought new O2 sensors this weekend. Front O2 sensor failures are really common.
 
Joined
Jan 2, 2006
Messages
844
Location
Breckenridge, CO
I was getting codes for awhile, PO130, PO133. After replacing both of my O2's (thanks CDan) no more codes. I got new bolts too, I'm not sure if they usually come with new bolts. I read lots of folks talking about their old hardware was all rusted, but my old ones didn't look too bad.
 
Joined
Feb 8, 2007
Messages
101
Location
Friendswood, TX
A failing or failed O2 sensor should not cause the engine to misfire.

-B-
Gotcha, I am guessing it will be a wiring fiesta for me. I simply don't like electrical gremlins, and having a solid foundation (wiring harness) would be worth the cost in peace of mind when I'm out in the boonies alone. Thanks again for the help.

Matt
 
Joined
Feb 8, 2007
Messages
101
Location
Friendswood, TX
Update: I got to looking, and thinking, (usually a bad thing). But this time it paid off. Little did I know, Toyota was kind enough to date the plug wires. Mine were sporting a born on date of 1996. So, i figured that after 178K, the wires had to go. After the Toyota man came through, I had a new set of plugs, wires, cap, and rotor. As I was pulling the plugs, to my horror, there was AC Delco written on the side of them. The PO must have been a cheap-skate, put in Delco plugs, and not even change the wires. The plugs looked well worn, the electrodes were no longer square and were nice and toasty. The cap and rotor looked no better either. It was definatly a :banana:job, and I can't believe how much better the old girl is running. I attribute the the miss on #5 to the dodgy plugs and the original wires. So far so good, no CEL, smooth runnings, and a little more pep in it's step.

OEM parts FTW!!
 
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