Service engine soon in my Grand Prix

[DeMasi1990]

Ok Now I have yet a new problem with the grand prix :thumbsup:.. I was comming off the parkway and came to a stop lightas I was making a left the Service engine soon light has come on....So i brought it to A advanced auto parts and had them run the code...


The Code came to be a P0420 code....and in the discription says " Catalyst Efficiancy Below Threshold" ( Bank 1)....I did a bit of reading on the internet about that and the options are...

1) I have a Faulty Catlytic Converter ( which is a month old )
2) My O2 sensor After the converter is Faulty ( has 87,000 miles on it)

This car is on the Expressway everyday, I dont Drive over 60mph ( anymore ) but from my moms house to work its a 5 min Drive, and I sometimes dont let the car warm up....

The dude at advance was trying to push me on the sensor ( and its not CHeap) so before I replace the both of them, does anyone know any specifics on that code? :lol: OH YEa!

I forgot to mention.. I stuck my hand over the exhaust and it smelled of unburned fuel.. like that " Rich smell" it wasnt horribly bad but the smell hasnt ever been there before ...also, I notice no loss of power when I nailed the gas a few hours ago

[GTP231]

Is it a high flow cat or a stock cat? The high flow ones are known to throw the code

[DeMasi1990]

Its a high flow. Made by walker, i think....but why would it do it now? and what explains the rich smell..if this is going to cause a problem in fuel efficiancy then maybe i should invest in a O.E.M cat...with the gas prices in long island, ny its too crazy
:coffee: And forget about the trans am... OMG, that car can suck a tank of gas down faster then I can fill it up...lol!...well shes not that bad, but for a V8 i will prob never see the milage i get with my grand prix...

[GTP231]

Might have taken this long to throw the code due to the drive cycles the computer needs to see with your driving habbits.
Did you ever get the EGR issue resolved?

[DeMasi1990]

GTP231, thanks for always getting back to me with answers to my Problems,as far as the EGR issue goes.............NO, I never got the EGR out of that Buick Regal, I actually did go to get it one day ( along with the whole top end of the Supercharged regal, and My Friend gave me this whole situation where he sold a Motor to this dude and the motor was bad and he has to give the motor to the guy and I cant take anything from it...So I forgot about it...I kinda figured that It was acting up originaly because the cat was getting plugged up .. It hasnt thrown a code since I cleaned it out...

Also, I do sometime smell a very very faint Rotten egg smell when I stick my head into the engine bay while running ( with caution ofcouse :lol: ).. ANd remember I also get that Rich smell alittle bit when I put my hand over the exhaust.. Ive been Monitoring my Fuel Economy and its Not Horrible, But not like it used to be...I used to get about 300 miles to a tank of gas ( mix of highway & City )...

Oh BTW do you know where I can get a Rear passenger side door for my Grand Prix. I turned into a box truck and my door got wasted:thumbsup:

[GTP231]

www.moradpartscompany.com
I'd do a tune up the car to be safe and see if you can find someone to scan the car too make sure the O2 sensor is in good working order

[DeMasi1990]

Originally ( I think I posted this)... The S.E.S light Was run and it was a Catylist Below threshold ( Which means the cat isnt working Properly Or something to that effect)...


I had a family get together yesterday and also a Job interveiw Yesterday..I put about 90 Miles of Driving around in my car yesterday, Filled Up on gas last night parked the car came out this Morning, and the service engine soon light is out...It comes on when I turn the key ( thats a check) But while running and Driving its been off, and hasnt come on all day....What would cause that?.. Maybe A difference in Driving? Or the fact that I need to go alittle faster then 55-60 mph on the highway every once in a while?

[DeMasi1990]

Originally ( I think I posted this)... The S.E.S light Was run and it was a Catylist Below threshold ( Which means the cat isnt working Properly Or something to that effect)...


I had a family get together yesterday and also a Job interveiw Yesterday..I put about 90 Miles of Driving around in my car yesterday, Filled Up on gas last night parked the car came out this Morning, and the service engine soon light is out...It comes on when I turn the key ( thats a check) But while running and Driving its been off, and hasnt come on all day....What would cause that?.. Maybe A difference in Driving? Or the fact that I need to go alittle faster then 55-60 mph on the highway every once in a while?

[93v8clone]

evap problems gas cap ;oose or suttin else stupid along those lines