My car is a 1999 456M, 6 speed, 30,000 miles. Several months ago the "Slow Down" light began coming on at start up. This was intermittent and did not seem to be related to anything. Since the catalytic converter was obviously not over heated I concluded the problem was a faulty sensor and drove on. Now the "Check Engine" light is on as well. A scan produced the following codes: P0422-Catalytic converter efficiency below minimum P0133-Oxygen Sensor Monitor A new catalytic converter is $10,000+-. Not a desirable expenditure! Dealer recommends replacing the oxygen sensors and the heat sensor for about $1300. This may solve the problem and maybe not. Then if necessary replace the cat. Are there after market or generic oxygen sensors that will work? Is there any repair short of replacement for the cat? I appreciate any thought or suggestion. Keith
Replace the O2 sensors first. If that doesnt work, you could do cat delete pipes and an ECU retune to eliminate the CEL. Much less than new cats.
I would confirm diagnosis first. All Ferraris are subject to ghosts. I would erase codes and drive the car and carefully note what code and what SD light actions occur again. Only when you get confirmation should you start chasing problems. Then you must manually confirm your diagnostic suspicions before you change the first part. Changing parts after the first appearance of codes is often a recipe for spending lots of money. SD2/3 testors may give you more specific info. and cut down on manual tracking of problems.
To change use Lambda sensors for $1300 is a joke. A really good from NGK shouldn't cost more than approx 100 euros. Ferrari lambda sensors are nothing special.
hmm lovely language.. it's good that you think faster than you write sometimes, it's just sad that ones fingers can keep up hehe.. Anyway, no it should not cost $1300 to change the sensors, Ferrari are using a standard narrowband sensor which is used by all car manufacturers. The excessabillity of the sensor in the car is not excellent but should not be a major problem. I also had a similar problem on my car and it turned out to be the controlbox for the cat temp sensor that was faulty. This is very easy to diagnose as you can swap the boxes around to see if the problem changes cylinder bank. Use the search in the forum and you find more information regarding this. good luck!
Thanks for the replys. They are all helpful. I swapped the control boxes sometime ago and there was no difference. So I do not believe one of them is faulty. Can anyone else comment on using generic oxygen sensors? Thanks. Keith
Keith- I have not looked at O2 sensors in detail, but there are numerous threads on the subject. Some of the wide band generic sensors will give warnings and should be avoided. I will take a look when I return. Too much trouble to do on a Blackberry. Taz Terry Phillips
After searching here and checking internet suppliers, here is what I found. Left front oxygen sensor: Dealer $400+-; Ricambi $309.95; Oxygensensorsforless.com, Bosch OEM direct replacement $104.20; a variety of universal replacements for under $50. Does anyone have experience with after market sensors? Any comment? Keith
Generally you might need to fix the connectors yourself but all in all if you buy one with the same amount of wires (lamdas use preheating) you should be ok. - Taz, do ferraris really use Wideband lamdas?? never heard that on a production car.? //joakim
Aftermarket sensors are not by definition wideband. I believe most aren't wideband actually. In most injection systems the lambda is only used as a feedback loop for better emissions, while the system will run pretty well without it. Widebands are for crude systems that can go non-stoiciometric, where the sensor is used to determine coarse measurements for the engine fuel/air ratio (such as in race injection systems and determining the fuel/air fields for engine management systems while tuning engines). However not all narrowband lambda's are identical either, there are differences between pre-cat and after-cat sensors, that's something to watch out for. Sorry to be a bit vague, just providing my $0.02, not gone completely in the deep end on this as I haven't had this issue (yet?). Wiki to the rescue: http://en.wikipedia.org/wiki/Oxygen_sensor
Joakim- No, Ferrari does not use wideband sensors, but many of the generic sensors like those sold on E-Bay are wideband to match as many cars as possible. Those types of sensors can, and probably will, give CELs and other indications of failure when used on a Ferrari. For Ferraris, it is better to use OEM or direct replacement sensors. The connectors match up that way, too. Replacement interval is 90K miles on late model cars (charcoal filter, too), but they do seem to wear out based on some unknown time, as well. Some of the pros like Brian or Dave may have a better feel for the time part of the equation. Dave Helms is also a Bosch distributor, so perhaps he has a recommendation. Taz Terry Phillips
Here is an update. I bought the Bosch sensors and they were a direct replacement. The old sensors had the same Bosch part numbers: 0 258 003 819 for the front 0 258 003 820 for the rear These sensors apply to 456, 456M, 550 and 355 after 1996. I bought four so the savings was about $1200.00. I suspect the appropriate universial sensor would work fine but would require splicing the plastic connector from the old units to the new. Hope this helps someone. Keith
