Not sure what model Eclipse you have so I looked up the GS with a 2.0l. The O2 sensors don't show a relay. They do have a heater element built in them to help them warm up faster. What kind of concern are you having?
Part of that is correct. The heater element will operate at 12v,but the part that senses o2 operates from 0-1v. With a scanner attached you should see it bounce back and forth like 0.3v to 0.8v and back down as it reads lean/rich. This should be tested above idle like at 1500 rpm. As far as a plugged catalyst,you can attach a vacuum guage to the intake manifold and raise the rpms. If the guage drops toward zero and stays there,you may have a plugged cat. At that point you can pull the o2 sensor out and/or back the exhaust off at flange in front of the cat and retest it. If the power loss is gone you have found the problem. Can you get the code that was pulled? I maybe able to narrow it down a little better. Good Luck. Let me know if you need more info.or if this doesn't make sense.Part of that is correct. The heater element will operate at 12v,but the part that senses o2 operates from 0-1v. With a scanner attached you should see it bounce back and forth like 0.3v to 0.8v and back down as it reads lean/rich. This should be tested above idle like at 1500 rpm. As far as a plugged catalyst,you can attach a vacuum guage to the intake manifold and raise the rpms. If the guage drops toward zero and stays there,you may have a plugged cat. At that point you can pull the o2 sensor out and/or back the exhaust off at flange in front of the cat and retest it. If the power loss is gone you have found the problem. Can you get the code that was pulled? I maybe able to narrow it down a little better. Good Luck. Let me know if you need more info.or if this doesn't make sense.
Answers & Comments
Not sure what model Eclipse you have so I looked up the GS with a 2.0l. The O2 sensors don't show a relay. They do have a heater element built in them to help them warm up faster. What kind of concern are you having?
Part of that is correct. The heater element will operate at 12v,but the part that senses o2 operates from 0-1v. With a scanner attached you should see it bounce back and forth like 0.3v to 0.8v and back down as it reads lean/rich. This should be tested above idle like at 1500 rpm. As far as a plugged catalyst,you can attach a vacuum guage to the intake manifold and raise the rpms. If the guage drops toward zero and stays there,you may have a plugged cat. At that point you can pull the o2 sensor out and/or back the exhaust off at flange in front of the cat and retest it. If the power loss is gone you have found the problem. Can you get the code that was pulled? I maybe able to narrow it down a little better. Good Luck. Let me know if you need more info.or if this doesn't make sense.