Maserati Forum banner
1 - 12 of 12 Posts

·
Moderator
Joined
·
5,887 Posts

·
Registered
Joined
·
50 Posts
Discussion Starter · #3 ·
thanks Travis,

but what can cause the catalytic converters to overheat? and when you say major problem do you mean they need to be replaced or the Engine is causing the overheating?

i don't have a OBD2 but i will get one soon.

thanks
 

·
Registered
Joined
·
744 Posts
The pre-cats (the front ones) overheat because they are a poor design. They are integrated in to the header which allows the car to meet a cold engine smog test but they fail prematurely and cost a fortune to replace. Running the car hard causes these cats to heat up very fast. The slow down indicator comes on as a warning to prevent the cats from overheating and the packing to then breakdown. If that happens you have a real problem as the packing could clog your main cats (farther downstream) or worse get sucked back in to the engine under a backpressure situation.

If the situation persists it will cause engine misfires, the ECU to put the car in to limp mode, and eventually the packing breakdown as described. The only permanent solution is to de-pack the pre-cats.
 

·
Registered
Joined
·
744 Posts
The diagram is a bit misleading because the pre-cats are not identified seperately.

#2 are the main cats - that is all that is needed to properly operate the car and meet normal emissions standards.

If you look between the arrows marked #1 and #3, you will see a flattened cannister integrated in to the header (just to the right of the gasket marked as #3). These are the pre-cats. To de-pack them, the tech cuts a square access hole in the bottom with a grinder, digs out all of the packing using a pick, and then welds the access cover back on. The downstream O2 sensor (located immediately behind the pre-cat) is then re-located to behind the main cat (this requires a longer sensor wire).
 

·
Moderator
Joined
·
5,887 Posts
thanks Travis,

but what can cause the catalytic converters to overheat? and when you say major problem do you mean they need to be replaced or the Engine is causing the overheating?

i don't have a OBD2 but i will get one soon.

thanks
There could be a number of things that make the slow down light come on. Don't jump to any conclusions until the car is checked out. It could be something as simple as a bad sensor.



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3
 

·
Vendor
Joined
·
4,731 Posts
Maserati's policy on this usually seems to be that they look for any scrape, scratch or dent and try to say that the bump or vibration loosened the material and caused its destruction. This is one issue that they seem to have difficulty stepping up to the plate on.

I'd definitely have a look under there and inspect them yourself before taking it in just to see what kind of shape you're in.
 

·
Registered
Joined
·
824 Posts
Maserati's policy on this usually seems to be that they look for any scrape, scratch or dent and try to say that the bump or vibration loosened the material and caused its destruction. This is one issue that they seem to have difficulty stepping up to the plate on.
Also, the EPA OMS can help with enforcing this. It is a US Federal Law that Maserati stand behind their products and protect our environment.
 
1 - 12 of 12 Posts
Top