99 4Runner CEL codes

[SaltyNaulty]

I just bought a 99 limited 4x4 this morning, and on the way home the CEL came on. The codes are P0125, P1130, P1133, and P1135. I was puzzled because it seemed to run fine with no misfires or anything, although it did smell a little rich, I got 21 mpg all the way home (135 miles).

I have read that the o2 sensors can cause this, and by replacing faulty sensors or repairing damaged wiring for the sensors the problem will go away. This is my first OBDII car, so forgive me for my lack of experience.
Oh, and I feel obligated to mention that it was originally a California vehicle, even though it is a Florida car now and it doesn't need to pass inspection will that have any effect on part numbers or compatibility? I just want to do it right the first time and get the CEL off.

Any advice is appreciated, thanks guys!

 

[fourwd1]

P1135: "Pedal position sensor A circuit intermittent".
P0125: "Insufficient coolant temperature for closed loop fuel control".

That's all I could find. The 1100 series are Toyota specific.

 

[TheDurk]

^^^^Nope. P1135 is A/F Sensor Heater Circuit Malfunction. Just change your front exhaust sensor. Get your Denso part number here: Find My Part | DENSO Auto Parts and then buy it on Amazon or rockauto.com for the cheapest price.The P0125 will go away then, too. Get new stainless nuts (M8-1.25) or dealer part no. 90179-08059 if you need them.

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/cip1135.pdf

 

[SaltyNaulty]

My part number for the upstream o2 sensor is 234-9002, $101 shipped off amazon but I'm gonna check with my buddy at the dealer before ordering to see if I can't get a deal. He mentioned something about the thermostat needing to be changed too, should I just go ahead and do that as well?

 

[TheDurk]

My part number for the upstream o2 sensor is 234-9002, $101 shipped off amazon but I'm gonna check with my buddy at the dealer before ordering to see if I can't get a deal. He mentioned something about the thermostat needing to be changed too, should I just go ahead and do that as well?

Waste of time and money if the only reason is the P0125 code. Dealers are good at that. If you still get it after the sensor swap, maybe, but I'd do more diagnostic work. Thermostat isn't even on the list of trouble sources for P0125. I'm 90% sure the sensor will resolve it.

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/di/eg5vzfe/cip0125o.pdf

Please report back on your buddy's deal.

 

[SaltyNaulty]

Just ordered the denso off amazon for $101, the dealer price with the buddy discount was $130 shipped and it wouldn't get here til Wednesday. I'll keep you posted as to what luck I have changing the sensor, thanks!

 

[SaltyNaulty]

It ended up needing an o2 sensor AND connector because it had melted the two connector pieces together on the exhaust. After replacing both and clearing the codes it ran fine for about an hour until it threw a P0420 catalyst efficiency below threshold code. It didn't do this before, only after I replaced the upstream sensor. What do I do now?

 

[Doc2012]

P0420 Error Code: Catalyst System Efficiency Below Threshold (Bank 1)

 

[4x4mike]

I have a CA version '99 with a 5 speed. When I got those codes it was my front sensor which is an air/fuel sensor on my model 4Runner. Not an O2 sensor so make sure before you buy parts.

 

[SaltyNaulty]

Yea I was able to get the air fuel sensor for the front, my buddy is a Toyota master tech and we worked on it a little bit, he says its the downstream sensor so I'll do that next and let you know the results.

 

[SaltyNaulty]

Ok so I replaced the rear sensor and cleared the code, and of course the light came back on. I'm thinking its the catalytic converter itself. It appears that someone has already welded in a "new" cat at some point, so what are my options? Do I get a magnaflow universal cat or something along those lines or do I have to get a factory Toyota cat? Keep in mind it is a California emissions car . . .

 

[4x4mike]

If it's CA compliant which cat has already been worked on? How do you know which cat to replace if not both?

A factory part will last the longest but most likely be the most expensive. I haven't read enough to know how the Magnaflows work long term.

 

[SaltyNaulty]

Just checked the temp before, on, and after the "cat" with an infrared thermometer. It was 220* before, 190* on, and 175* after. This leads me to believe that some jabrony wannabe shade tree mechanic welded in a resonator instead of a cat. So I think I'm gonna check prices and see what I can get. If anyone has info on the aftermarket universal cats please chime in!

Thanks guys

 

[SaltyNaulty]

4x4mike its the second cat that has been replaced, looks to be the stock one upstream

 

[Robb235]

Just checked the temp before, on, and after the "cat" with an infrared thermometer. It was 220* before, 190* on, and 175* after. This leads me to believe that some jabrony wannabe shade tree mechanic welded in a resonator instead of a cat. So I think I'm gonna check prices and see what I can get. If anyone has info on the aftermarket universal cats please chime in!

Thanks guys

Just curious, but what good did those infrared readings do? Should your temp readings have been something else? I guess I'm confused as to why those temp readings make you think you have a resonator instead of a cat

Can you take a picture of the resonator/cat in question?

 

[SaltyNaulty]

The "cat" should be significantly hotter than the surrounding pipe, like 100-200 degrees hotter.

Here's what I have

 

[SaltyNaulty]

That was my upstream o2 sensor connector. That was the cause for my first set of codes and now it's just the p0420. Anyone have suggestions as to what I should do about a replacement cat? Magnaflow, catco, walker, dynomax . . . Any of those work?