Oxygen sensor

[IRA51]

What part of Jersey are you in? if your in or the Morristown area stop in and see my buddy Fred Finley at 4 early street and he will scan it for you . you can check the O2 sensor with a DVOM but if you want tho know the A/F ratio you will need to drill a hole in the head pipe and insert the probe to get a good reading ,than weld up the hole after your done. just what are you trying to find out ? the upstream O2 is to measure the amount of oxygen in the exaust and send the info the the computer to trim the fuel to close to stoichiometric 14.7 lbs air to 1 lb of fuel . if you use a DVOM you will see that as the voltage goes higher you will be richer and as it drops you will be leaner. the down stream o2 is to measure cat efficiency. if you do not have a MIL light on than you are probably in range and all is well. OBD II IS YOUR FRIEND ,if you have a good full function scaner or get someone who has one to scan it you will know whats up . good luck if you have a MIL light on you can try auto zone and they will be able to check for codes .