I have a 1997 Toyota XLE V6 3.0. I got this car from my uncle with about 222k miles on it. Its had a lot of use but it was also treated well, serviced regularly, and owned by my uncle the entire life of the car. I've put about 4k more miles on it since I got it.

The problems started with a sort of rattling noise between around 10-25 mph. I didnt think anything of it because I had no other symptoms, no power loss or anything like that. It also went on for so long and never changed or got worse that I sort of stopped even noticing it.

Then the other day I stopped at a stop sign and when I put my foot on the brake the RPMs dropped down to about 500 and the car started to sort of "rock" back and forth while the RPMs bounced around from about 400 to 600 and the engine made a weird sputtering noise, but didnt stall, then the check engine light came on.

I took it to a friend that is a mechanic and left it with him for a few days. He called me up and ran off a list of problems his guys found with it and the codes the engine put out, which had to do with multiple missfires.

He cleaned out a bunch of stuff, found that the water pump was bad and the coolant tank was cracked so he replaced those, he got a tensioner for the timing belt and also got an idle pulley. (I have no idea what any of this stuff is, I'm just reading off the bill.)

So he picks me up in my car, its running great, drives back to his shop, running great. Felt more powerful, sounds were all gone etc. Pay for it, start the car, put my foot on the brake...RPMs drop, check engine light pops back on, car almost stalls, starts rocking.

I yell at him, he comes out, they pull it back in, he runs some tests, they take some stuff out, clean some solenoids, do some other stuff I didnt understand...I come back a few hours later, guy pulls it out, does exactly what I did before, no problems. Turns the car off, I get in, put my foot on the brake...problem comes back. Dude looks stumped, hooks the computer back up...multiple missfires again.

So they pulled the spark plugs out and check the wires, then get new plugs because the old ones were corroded.

I go pick it up for the third time today and it runs great, all the problems I had before are totally gone, drive it around the block, everything works great, get halfway home (no issues) check engine light comes on.

I take it back, he runs the computer, o2 sensors both reading as bad. But we drive it around for awhile and get it up to speed and have no problems, he says the o2 sensors will probably affect my fuel economy a little but I dont have to replace them right now, but that if I want to they're probably about 85 a piece plus labor.


My questions are these:

A known problem before all of this was that both CV axles were shot, so right off the bat I had him change those out. So keep that in mind

He spent -

Left axle $84.18
Right axle $98.17
Coolant tank $70
Tensioner $60.08
Idle pulley $31.16

for a total of 343.59

Labor 5.6 hours @ $75 an hour $420

Tax $29.20

Total: $792.79

Everything after the first time was free of charge including the plugs and all the labor, which it should be. Do these prices seem appropriate for the work that was done?

Also, how much of a problem are those o2 sensors really going to be?

 

Your mechanic prices seem OK.

The engines computer monitors 02 sensor performance. The engine has more then one 02 sensor. If an 02 sensor trouble code is generated, typically the code is specifies which sensor is bad as all sensors don't fail at the same time.

As to 02 sensor problems. MPG may drop, engine operational problems, sometimes there are no symptoms. If the MPG drops the engine is running too rich which can be hard on the emissions converter and effect its life.

Is the engine running OK now?

What exact codes are being found?

 

I dont remember the exact codes but it had 2 codes for 2 different banks, something like error x bank 1 error x bank 2, error y bank 1 error y bank 2.

The engine seems to be running fine now, better thank before at least.

 

Bank 1 is the rear cylinder nearest the firewall, Bank 2 is nearest the radiator.

Check the link for part costs discount retail prices. Price depends on what 02 sensor and if the car was built to California emissions or Federal standards.

1997 TOYOTA CAMRY XLE Oxygen Sensor

Keep an eye on MPG, if it drops the engine is running rich, bad for converter.

 

I've driven it about 40 miles on a fresh tank of gas since the repairs and the check engine light has yet to come on. I'm wondering if its possible it was a bad reading?

My gas also hasnt even dropped to the "full" mark which after 40 miles before it probably would have so...I have no idea.

 

Possible.

If the mechanic cleared any trouble codes from the computer and the problem is still present, it will take some driving before the codes are set again. The computer needs to go through it diagnostics again at least twice, if the tests fail the code(s) will be set again.