Hi,

I moved from Texas to California and am trying to decide if there is any hope of passing the emissions test here without exceeding the value of the vehicle with repair costs. The mechanic who did the check said it would not be worth trying to pass but I see my same year/model driving around the city so I'm still holding out some hope.

After doing an OBD scan I noticed that one of the O2 sensors (sensor 2) is staying at 0 volts with no changes so I'm guessing start with replacing that and finding the emission leak before trying to replace the catalytic converter etc. However, I am still learning abut vehicle repairs so I thought it would be a good idea to reach out and see if this sounds like a reasonable goal or not.

This is a 1998 V70 Wagon 2.4L with 227,000 miles on it.

Codes that appear in OBD system check:

1:P0300Random/Multiple Cylinder Misfire Detected
2:P0303Cylinder 3 Misfire Detected
3:P0455Evaporative Emission System Leak Detected (large leak)
4:P0422Main Catalyst Efficiency Below Threshold Bank 1
5:P0302Cylinder 2 Misfire Detected

This may be too much to throw in one post but hopefully someone will know if this scenario is familiar or have had similar problems.

Thanks!

 

There's a few things you will need to sort out. 1) vacuum leaks can appear as O2 sensor fault codes 2) misfires can be spark or mixture related. If you haven't done a top end tune up, plugs/wires/cap/rotor/coils etc, time to do so to baseline the tune. I'd probably start by inspecting all vacuum lines first - there's a specific line that goes down under the car for the evap system so you may need to get a smoke tester to find a leak that's not obvious. After that I'd do the full top tune up - cap/rotor/wires/plugs/air filter. Then if you are still throwing codes, you can measure up the O2 sensors. You may have two O2 sensors - front and rear. Both are four wire designs - two wires are for the heating element (power/ground) the other two are for the sensing circuit. Make sure you measure the correct pair. Not sure if you can get to the connector but its possible to slide a paperclip etc into the back of the connector to measure voltages with the car on and the harness connected... Probably just easier to replace if the parts are of unknown age/condition.

 

Thanks, I didn't know the vacuum lines could be throwing off the O2 sensors.

 

Before you sink too much money into guessing, you should know you are most likely going to need a new cat, which won't be cheap.