Smog Help

[The Critic]

My mother has a 1996 Saturn SL2 with 96,100 miles on it. Tomorrow, I plan to replace the following items prior to having the vehicle "smogged" in hopes of avoiding the problem I had last time: (More on that later)

- New NGK Copper Spark Plugs
- New ACDelco Spark Plug Wires
- New ACDelco PCV Valve
- New Maxlife 5w30 Engine Oil + Purolator PP Oil Filter
- Clean EGR valve
- Clean Throttle Body
- New Fram Airhog Air Filter
- New Wix Fuel Filter
- New Valve Cover Gasket
- Sand contacts on coil pack towers

During the last smog inspection in 10/04 at 76,299 miles, the vehicle barely passed (on the second try) due to very high Hydrocarbons. Per my records, the spark plugs, air filter, oil, and fuel filter were all replaced about 7000 miles beforehand. One thing to note: it was found that the spark plug tube seal on cylinder #1 had been seeping oil when replacing the plugs at 70k miles. It was NOT repaired, and won't be until tomorrow. However, would this be the cause of my problems? At 76k miles, I didn't think that the Oxygen Sensors or Catalytic Converter would fail so soon.

Here's a scan of the last smog results:

Any help/suggestions for improving my results is greatly appreciated.

Thanks!

 

[TheLoneRanger]

Mr Critic, I remember reading that Saturns had an oil control problem, maybe weakened oil wiper (piston) rings or something.....? If the vehicle consumes a little oil, this would confirm it.

If that's correct, and the high HC is coming from burning oil, then I'd use a higher weight oil for testing, then change it back to the 5w30 afterwards.

You could also pour a can of "Restore" in it before testing, and then drain it out afterwards. (Many on this board would want to hunt me down and kill me for suggesting this, but hey, anything to get a pass on the smog test.....

 

[Gary Allan]

I don't know about the O2 sensors. You're looking at 76-9Xk ..I'm looking at 10+years.

You're only looking at the upstream one anyway.

 

[m2200b]

I see high NOX and High HC and a possible EGR blockage but cleaning and inspecting the EGR is on your list so it may clean them both up.

 

[The Critic]

Let's hope so. New NGK copper plugs and Delco wires are in as of tonight, along with 4 qts of Maxlife 5w30, Purolator PP filter, and some carb cleaner. :wipeshead:

 

[The_Jeff]

EGR is a good idea for fighting NOX as is having the car at thermostat temp (195'F) and not cooling fan temp (230'F). If they make you idle it, hit the AC so the radiator fan comes on and cools it down a little.

 

[Quickbeam]

Good cat will knock donw HC so it may be tired. Upstream numbers would be helpful but I understand they're hard to get. Could be oil or a leaky EVAP system. Valves adjusted? O2 shows the engine is running a tad lean. Could be where the NOx is coming from.

 

[Quickbeam]

At 15 mph the lambda calculates out to 1.115 or an A/F ratio of 16.39. At 25 mph it calculates out to 1.125 or an A/F of 16.54. Too lean. Could be pirate air or a lazy O2 sensor.

 

[Lonnie]

On an old car I went to thicker oil, 20w-50, and Fuel Power in the gas after a failure and it passed. I used 2 ounces per 5 gallons of gas. The failure was a high NOX reading.

 

[The Critic]

Quickbeam, thanks for the help.

So, O2 Sensors and Catalytic converter on the list for replacement? Which O2 sensor should I replace?

Thanks.

 

[The Critic]

$180 for new OE 02 sensors. Before/After.

$95 for new cat if it's Tier 1, $508 if it's LEV. (OE)