Failed Emission Test with high NO(PPM)

SOURCE: wont pass emission ''hc to high" !

1993 DODGE CARAVAN 3.0 HCPPM LIMIT 144 READING 172 NO PPM LIMIT 965 READING 1024

Dan De Groote

• 35 Answers
• Posted on Jun 01, 2009

SOURCE: saturn sl2 emissin problem

If the SES light is on, take a paper clip bend it in a u-shape and jump the scanner input positions A B. This should flash the ses in sequesces to give you the trouble code, Please see the following link. http://www.troublecodes.net/GM/ Refer to the code to see what the issue may be. SES lit means that there is a emmissions related issue. Refer to the other links for additonal information on O2 sensor resistance, and the egr valve solinoid. Check the EGR is relitive easy for operation. Remove the vaccum hose and place a hose of similar suckon the hose to pull vaccum if the diafram underneith retracts, hold the vaccum by plugging off the tube with your touge if the diafram retracts, will not hold the vaccum, it is bad. The solinoid should read 40-60 ohms if good. http://www.saturnfans.com/forums/index.php http://www.aldlcable.com/sc/pages.asp?pageid=21
http://www.saturnfans.com/forums/showthread.php?t=37884

SOURCE: Failed 3 tests with emissions

Clean up your mass air flow sensor and check the map sensor...both can mess with ignition/fuel settings. Neither may be out of range enough to give you any performance problem but together they can do that. If you are going to add race fuel, it may also help to add 3oz of acetone per ten gallons of fuel. It vaporizes faster than gasoline and burns cleaner. It will also clean your injectors. A slight egr malfunction can also throw off readings but will not show up as a problem unless it becomes worse, but usually shows up as an idle problem first.

SOURCE: My 1993 Saturn SL2 just failed the Smog Check

change your O2 sensor.

SOURCE: failed smog check

How well does the vehicle run?

Assuming that the engine did pass the EGR function test on the emission test results, and the MIL (Malfunction Indicator Light) or check engine light is not on when the engine is running, and if you are not sure when the last time it was that the engine had a complete tune-up, with distributor cap, ignition rotor, spark plugs, spark plug wires, air and fuel filters, then a complete tune-up would certainly help, and if the engine oil and oil filter have not been changed in a while, then they should also be changed before an emission test because long used engine oil traps carbon and it will show up as higher CO on the emission test because the emission analyzer will be able detect the higher CO from the engine oil through the PCV valve.

However, it would seem from those HC readings that there is a vacuum leak, and carefully inspect all of the vacuum lines for any cracks or damage, (especially the vacuum line to the fuel pressure regulator) because cracks in the vacuum lines seem to like to hide underneath the lines.

The emission label under the hood should have the vacuum line routing diagram printed on it, and the vacuum lines should all be checked to be certain that they are all connected correctly.

Here is the firing order diagram for that vehicle to help assist you tune-up the vehicle.