Need help SES, Service Emission System

[john19999]

My Seville 96 is giving a message consistently Service Emission System and Service Engine Soon indication. When I stop at traffic light, every few seconds, it seems the car may die but it does not. The code I checked was PC0147 Current. I could not find out the PC codes but I was able to find out P0147
P0147 - Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 3

I changed spark plugs about a year ago but did not change the spark wires. Sometimes I think it could be plenium vacum leak.

Car is running great. However the emission test is due in couple of months so I have to resolve this issue. Can you please share your ideas. What does this code really mean. Is it referring some misfire. If so, which spark plugs?

Thank you so much for your help!

Thanks
John

[chubbyranger]

96 is the evil year of OBD II conversion so your codes may be challenging to find. Not sure how you're getting from an O2 sensor code to misfire when you state the car is running great. Since you are getting an SES light with an emissions warning and an emissions code I would have that O2 sensor changed. Not sure how 96 N* is set up but that may be an O2 sensor near the catalytic converter.

[Ranger]

It is the AFT-CAT sensor.

[submariner409]

John, I think the 96 did not have the plenum problems which affect 2000+ models.

Go to Walgreen and pick up a cheap stethoscope and lengthen the tube with a piece of vacuum hose. Use the rig to snoop around the intake manifold, including inside the end near the p/s pump, and listen for vacuum leaks. Test the vacuum nipples and fittings on and to/from the throttlebody area. Make sure the PCV piping is properly attached, especially from the PCV valve/orifice (rear cam cover) to the intake manifold.

I'l also throw in my standard "run a 20 oz. jug of TECHRON with your next fillup".

Put your car, year, mileage, and location in your profile.

[john19999]

Thank you for your feedback

Are there more than one O2 sensors? Regarding Ranger's comments "It is the AFT-CAT sensor". What is AFT stands for. What could be the location of the sensor. I know that my car is leaking oil. It is possible that the sensor or the wires ight have been damaged. Any ideas how to check if it is sensor or wires?

Thanks
John

[submariner409]

AFTer cat. Between the cat and resonator, right side of the exhaust pipe. Maybe 3 or 4 total O2's: each exhaust manifold collector area and maybe pre-cat. Not sure for your year.

Buy a real Helm (www.helminc.com) GM Factory Service Manual or subscribe your individual car to www.alldatadiy.com .

[dwight.j.carter]

Originally Posted by submariner409

John, I think the 96 did not have the plenum problems which affect 2000+ models.

Go to Walgreen and pick up a cheap stethoscope and lengthen the tube with a piece of vacuum hose. Use the rig to snoop around the intake manifold, including inside the end near the p/s pump, and listen for vacuum leaks. Test the vacuum nipples and fittings on and to/from the throttlebody area. Make sure the PCV piping is properly attached, especially from the PCV valve/orifice (rear cam cover) to the intake manifold.

I'l also throw in my standard "run a 20 oz. jug of TECHRON with your next fillup".

Put your car, year, mileage, and location in your profile.

What plenum problems do you speak of ?

[submariner409]

In the OP post #1 he mentions "the plenium (sic) problem". I don't think his car has that particular vacuum bugaboo.

2000 and later plenum (the convoluted rubber bellows attachment clamped between the TB and intake manifold) cracks are a constant source of attention here.

[john19999]

I manually reset the PC code (PC0147), the Service Emission System and SES has gone away. Now there is only one problem. At stop light, the car sometimes seems as if will die but does not. Every a few seconds, there is some kind of jerk (rpm slight lowers), but car does not die. Could it be fuel injector needs cleaning, spark plug wires need to be changed, or vacuum leak. Any ideas please?

Thanks
John

[chubbyranger]

Check the fuel pressure regulator. Also, the EGR valve may be carboned as well but I don't recall if that causes idle issues unless it is not closing correctly.

[john19999]

Does anyone know how to check Fuel pressue regulator. Where is it loacated? Aos where is the EGR located and how to check it

Thanks
Johb

[john19999]

Does anyone please share where is fuel pressure regulator located and how to check it. Similarly where is the EGR located and how to check it.

Thanks
John

[Ranger]

Check the Tech Tips section for a tutorial on the FPR. It's very easy. The EGR will set the SES light and a DTC if it is not operating properly.