2002 saturn engine codes p0305,p0421 & p1818,what needs to be done to correct problem?

https://www.google.com/search?sxsrf=ALeKk01VFr0wDrLUx_ixS3OmYDCES58ofg%3A1584714228350&source=hp&ei=9NF0Xq-cE62IlwTgjbCQAw&q=how+to+fix+code+P0305+on+a+2002+dodge+caravan+3.3+liter+engine+engine+light+on+%2C+running+rough&oq=how+to+fix+code+P0305+on+a+2002+dodge+caravan+3.3+liter+engine+engine+light+on+%2C+running+rough&gs_l=psy-ab.3...1718.1718..2639...0.0..0.257.257.2-1......0....2j1..gws-wiz.zE46-pnWnww&ved=0ahUKEwiv5pjFoKnoAhUtxIUKHeAGDDIQ4dUDCAU&uact=5#kpvalbx=_XtJ0XufFNJGPlwTPyYHIAw36

No, but fix the oil level before you damage the engine.
The code is the O2 sensor , past the catalytic converter, either you have a fouled spark plug, a bad converter , or a bad O2 sensor.

Start with a tune up and change your fuel filter. Check your plug wires or better, replace them. The p0421 code has to do with the cat. Also, install spark plug anti foulers, you can get them at your local auto parts store. Follow the spark plug link. As for p1818, have this code reset at a reliable shop preferably a transmission shop. Ask around and some of your friends for their recommendations as to where you can take your car to to have the trans control module reset without the shop trying to tell you you have to fix something, ie shell out the big bucks. tell them aLl you want is to have the code and trans reset, NOTHING MORE. Sometimes this code comes up false. so have it reset after you take care of the tune up etc. this code should be reset using a transmission code reader.

code p0700 refers to transmission control system malfunction==causes wiring-- TCM= replace the TCM . Check with the dealer to find which servo/ sensor p1818 refers to but it may also be related to the TCM.

Try this site - good resource for OBD-II codes and possible diagnostic steps.

po421 warm up catalyst efficiency below threshhold bank 1, 431 same on bank 2..

taken from: http://forums.evolutionm.net/lancer-troubleshooting/349095-code-p0421-call-mitsu-before-you-do-anything.html

Code P0421- Call Mitsu before you do anything! Icalled my nearest dealership today and for those who dont know, if yourcheck engine light is on and its showing fault code P0421 this may befrom a factory recall on the warm-up converter and a PCM reflash.MILEAGE OF THE CAR DOES NOT EFFECT THIS RECALL. Anyone whos had problemwith a dealership not doing the repairs because of mileage needs tocontact another dealer or the owner of the dealership. This is what theservice manager told me today so though I'd share. Getting mine fixedtomorrow at 10am, I cant wait.

For more information about this code Google "Fault Code P0421" You'll get tons of information Last edited by Swankzer; Jun 2, 2008 at 12:31 PM.

taken from: http://forums.evolutionm.net/lancer-troubleshooting/349095-code-p0421-call-mitsu-before-you-do-anything.html

Code P0421- Call Mitsu before you do anything! I called my nearest dealership today and for those who dont know, if your check engine light is on and its showing fault code P0421 this may be from a factory recall on the warm-up converter and a PCM reflash. MILEAGE OF THE CAR DOES NOT EFFECT THIS RECALL. Anyone whos had problem with a dealership not doing the repairs because of mileage needs to contact another dealer or the owner of the dealership. This is what the service manager told me today so though I'd share. Getting mine fixed tomorrow at 10am, I cant wait.

For more information about this code Google "Fault Code P0421" You'll get tons of information Last edited by Swankzer; Jun 2, 2008 at 12:31 PM.

Hi,

So you have a P0421.

A code P0421 may mean that one or more of the following has happened:

• The catalytic converter is no longer functioning properly
• An oxygen sensor is not reading (functioning) properly
• A sparkplug is fouled up

As far as running conditions if it performs normally, you most likely need a catalytic converter. The good part of this is there shouldn't be any abnormal running conditions, so it should be fine unless the engine is running very rich for some reason. (it will usually smell badly when this happens) However, on rare occasions the cat can get hot and melt down causing an exhaust restriction..bad gas mileage, low power, and possible fire potential, but most likely this is not the case. (this is generally speaking here and covering all the bases... )

The most common thing with P0421 that the fuel injection computer detects that the cat is not performing to federal specs an need to be replaced. You will need to have it fixed before your vehicle inspection.
Good luck and I hoped this helped you.

Correct, but it is sometimes more difficult without help and the proper tools. First make sure it is not just the belt squealing.