Camry 02 SE V6 - Replaced Spark Plugs - Check Engine Light Came On - What's Wrong?

[I.B.]

Dear All;

I recently replaced the spark plugs on my 2002 Camry SE V6 (Gen 5). Let me just say that it was INCREDIBLY DIFFICULT to reach the rear 3 plugs as they sit underneath the intake manifold, way to the rear of the engine compartment. To reach those, I had to unplug some wires reaching on
top of the engine, then loosen the intake manifold.

Along the way I broke a tiny air valve that sits underneath intake manifold, and replaced it right away, before starting the car.

When everything was put back together, the car started wonderfully, only to notice the engine light come on. I had the codes checked at the dealer and they indicated a malfunctioning Catalytic Converter and A/F Sensor and some other emissions stuff. Later that day, the VCS/TRAC OFF light came on as well. The service guy at the dealer said those typically come on together with the Check Engine light, which sounds like something he pulled out of somewhere!

The car drives well, no hesitation, no weird behavior, but has no traction control, naturally.

While loosening the manifold I had to use a little force to flex it out of place. My guess is that it I may have yanked something out place: may be a wire issue, or a sensor.

What are your guesses?

Thanks in advance!

[toyomoho]

Typically the codes are very specific, what were the codes?

The other trouble lights will most likely clear up when the reasons for the CEL being on are fixed.

[TRD VVTi]

What the technician told you was true. He didn't "pull it out of somewhere" other than factual knowledge.

I'm guessing that you have a vacuum leak, possibly from the intake. Without you stating what the "other emissions stuff" is, it's hard to help you. If you want accurate advice, you should give accurate information.

In the future I would recommend that you bring your car to a professional. As you don't appear to know what you're doing, or what other people are telling you, having a pro do it will likely save you money and time in the future.

[darksparkz]

Try resetting the ECU, either by pulling the ECU fuses or pulling the negative terminal on the battery.

Also, see if you can borrow an OBD scanner and try to clear the codes after that, and see if they do reappear after a few days.

But having the code numbers would be helpful.

[I.B.]

Thanks for the replys and helpful hints everyone. I checked my service record, but it does not list the CEL codes, only the description. I will try to get you the actual CEL codes from the dealership service department on Monday.

[I.B.]

OK guys, here are the CEL codes:

P0420
P1135
P1155

[darksparkz]

http://www.autoshop101.com/forms/h37.pdf

Most of those codes pop up when the O2 sensor fail, or are malfunctioning. You can do a voltage test for them

P0420 can be any of the O2 sensor, or the cat itself.

But the P1135 code is related to the air/fuel sensor, there could be a short in the sensor itself, or check Bank 1 Sensor 1 O2 sensor, I believe that is located closest to the firewall itself, Sensor 1 is in front of the cat.

Look at: http://www.obd-codes.com/ if you want to fix it DIY, otherwise, dealers may charge a lot to replace all 4 O2 sensors.

P1155 is definitely the B1S1 O2 sensor.

[I.B.]

Thanks a lot, darksparkz. This is very useful info.

I am thinking the O2 sensor nearest the firewall may have gotten damaged as I was trying to loosen the manifold to gain access to the spark plug set underneath it.

One interesting thing I notice about the VSC/TRAC OFF light: Every time I start the car the light comes on delayed, and not right away. In fact, I do get traction control for a few seconds (I tested it in snow). The light then comes on, and traction control is no longer available. What could be the reason for this? Teetering connection somewhere?

Also, what's the worst that can happen if I continue to drive with a failed O2 Sensor?

[darksparkz]

Possibly bad fuel economy, and wouldn't pass emissions. Possible loss in performance as well. But I don't think there are any long term damages to the engine itself. I think with a bad O2 reading, you have a chance of damaging the spark plugs by fouling them, that's just a guess on my end though.

As far as the VSC light, I'm not exactly sure about that, if you have a VSC button under your dash, typically next to a tire pressure button, then you might be able to reset it. Or a dealership should be able to reset it and see if its tripped again. I've heard stories of people having their VSC lights coming on when they fill up on gas with the car on, odd indeed though.

[new echo owner]

Did you tighten the ground wires are the back of the intake plenum by the bracket? And the one by the right side of the plenum?

N.E.O.