egr+lean code => misfiring - HELP!!

[Leadfoot77]

So I sold my solara to my sister a little while back and she's running into some problems... this place was always very helpful when I owned the car so I thought I'd give you guys a shot (don't know what happened to my old account... doesn't seem to work so i had to create a new one???).

Anyways, she got a check engine light - had the codes read and they were basically egr stuck open + system running lean.

I searched this forum and went to clean her EGR - I was in the basement getting the multimeter to test the o2 sensor and told my sister to pop off the nuts on top of the egr valve - well she made a mistake and tightened them... shearing two of the studs off

I tested the O2 sensor and it did not pass the test (at least the one in Haynes manual - fluction from .1 to .2 open loop then .1 to .9 closed loop.. it just stayed .3 the entire time). So she goes to <insert part store> and picks up a bosch replacement that you have to wire in yourself... .my father and my sisters boyfriend wired the thing to the old connector and we installed it...

she calls me later saying the car is running rough (misfiring). She takes it to the dealership and they want to charge her $1500 for 1) a toyota o2 sesor because the "aftermarket" ones cause cel codes , new egr valve (yeah we saw this one coming), all new spark plugs (she had them replaced at 90k - car is probably a little over 100k now), and a lubejob on the shifter cuz it's stick


so i've used replacement o2 sensors before without a problem (not sure if i did on the solara or not) - has anyone here had any problems with part store/bosch o2 sensors?? I realize its possible it was wired wrong but i'm not sure that that would cause the degree of misfiring that is going on ... she says it will not move at all and then suddenly go while on the gas - i'm thinking all 6 cylinders are misfiring...

originally i thought it might just be a vacuum leak at the egr valve.

She agreed to get the egr valve replaced adn the spark plugs. She gets it bakc and hte car is pretty much the same. So that leaves the o2 sensor or something totally else...

Any advice or knowledgeable responses out there??? I'd greatly appreciate it...

Thanks a lot!!!

[orlin03]

There should be two different Bosch sensors available; one that you wire in yourself, and one that plugs into the harness. Sometimes the parts stores only stock one or the other; whenever I order one at the shop and they send me one like they sent you, I send it back and make them send me the replacement one. The Bosch should be warranteed, so tell them you want a new one that comes complete with the connector installed.

[Got2XLR8 NYX]

Update? I have the same problem and the Misfiring on all 6 cyl. started for me Yesterday!

[Eye8Pussies]

^ did it throw a code?


and misfires are usually associated with vacuum leaks, so test for that first

[Paladin06Greg]

With both the early and late-style air flow sensors, vacuum leaks can cause driveability problems by allowing unmetered air to enter the engine. Air leaks around the throttle body, injector O-rings, intake manifold gaskets or vacuum hose connections can cause the air/fuel ratio to go lean. So if you find a code 25 (lean air/fuel ratio), start looking for leaks.

Another often-overlooked cause of air leakage is the EGR valve. If the valve sticks open, it will act much like a vacuum leak, causing a lean misfire at idle and hesitation problems.

[Bigdawg103]

I'm not sure if this info will help, but my 02 Solara was misfiring and running on 3cylinder, it triggered the check engine light and whenever I gave the car gas it would choke or stutter. I bring it to toyota and they check the codes and within in 10 mintues they fix the problem. It turns out it was the emission coil.
I watched the mechanic remove the platic cover to the engine and then he remove the bolt that holds the emission coil in place. In my case I have a 4cylinder engin so it was the emission coil above the # 2 cylinder. He pulls it out and puts in a new one starts the car and vroom no hesitation and it's been about 2 weeks now. Hope this info is useful to you.

[PDX SuperSolara]

First of all, a leaking EGR valve will cause a lean code, because the exhaust that is getting in at idle is unmetered. Second, Bosch oxygen sensors don't work in your car. Get the NGK direct fit, that means no splicing of wires! If the plugs are only 10k old they should be OK. If the EGR is fixed, by cleaning, that should be OK too, if sis broke the studs on the bottom though, you have to replace it with a new or good used, or replace the studs or use nuts and bolts. The EGR fittings like to leak air so be sure they are sealed well.

P.S. Thet is not "emission coils", its ignition coils!