93 v6 xle failing emissions

A few days ago I took my 93 v6 xle in to have the emissions tested. I failed with 280ppm/120ppm on the low speed and 180ppm/130ppm on high speed. This is really frustrating because I just had tons of work done on the engine about a month ago. I went back to the place where I got the work done, which claims to be a toyota specialist, and they told me I needed a new O2 sensor. So they replaced that and tested it again. Failed. Well all of a sudden they remember there is another sensor; another $130. Failed. So $2000 later im left with an illegally polluting camry thats worth about $200 less than that.

Does anyone have any ideas? All help is appreciated. BTW I live in Houston, TX where the emissions standards are pretty high.

That's a very typical rip-off. Did they test the sensor before they replace it?
I live in mid atlantic, we have different emission test here. You can try take off the EGR valve and see if it's clogged by carbon deposit. Clean it up may help you pass the emmision test.

If it fails emmissions there must be a code in the computer pointing you in the right direction of failure.This is what they should go by and is not rocket science.

I am a Toyota technician. I have seen many older cars that are almost impossible to get to pass. I would say that a lazy O2 sensor is a good 'guess', but it is usually just that, a guess. I would check all the ground points on the engine. There are a few grounds on the back of the plenum. I have seen loose grounds cause havok on emission readings. There is a good possibilty that your catlytic coverter is bad. Have the timing checked, the grounds checked, and make sure that you have the car good and hot when it is tested. A cold converter will not work as well as one that is good and hot. If you need to wait in line for the test, put the car in park and rev it up to about 3000 rpm for a while (2-3 min).
Good luck.

A fresh oil change also helps on an emission test.