Bad Flow - Rough Acceleration

[matthewaqui]

Hello F-bodies,

I read quite a few post in this forum regarding the Catalyst Converter and P430 Code. I have the following codes:

P0119 Generic
IAT Sensor 1 Circuit
High Input

P430 Generic
Catalyst Efficiency
Below Threshold
(Bank 2)

P430 Generic PD
Catalyst Efficiency
Below Threshold
(Bank 2)

I have a 2000 Silver Trans Am with 120,700 miles on it. I was hoping that I could keep the vehicle running until next year and upgrade to a 2010 Camaro. Just today I'm experiencing very rough performance on my TA, typically upon startup. When I accelerate, the vehicle slugs and does not fire..... there is very rough idling of sort. This complication was very evident today for it took awhile for the vehicle to get out of this poor performance stage.

Once the vehicle gets through the sluggish torment, acceleration is alright.

This problems reminds me of when I forgot to plug in my right side coil wires in after replacing the plugs.

Would a bad Catalytic Converter cause a back flow and choke ignition causing no acceleration and very rough idle?

Any suggestions would be greatly appreciative.

Matthew

[JoshieDoom]

Bad Cats can cause a lot of problems... If you have to have them get new ones(emissions bullcrap).. if not.. get rid of them and turn the code off(via a tune). and your IAT sensor probably just needs to be replaced... Simply fix..

[matthewaqui]

Thanks for the word Josh...... as I was idling in drive..... I seem to here a low rattle from beneath, thinking the Driver side cat is bad inside. I'm in California and will need those Cats.... thanks for the advice buddy.

I have heard other experiencing the acceleration stumble that I have had, though there has been no advice posted...

Matt

Bad Cats can cause a lot of problems... If you have to have them get new ones(emissions bullcrap).. if not.. get rid of them and turn the code off(via a tune). and your IAT sensor probably just needs to be replaced... Simply fix..

[matthewaqui]

Well Josh,

I called GM and they will replace the cats for me at no charge. I'm over the 120,000 miles warranty at 120,800 but explained I bought the vehicle used 110,000.

I think that is the problem of some backflow restrictions causing all sort of bad performance.

Once again, thanks man!
Matthew

Bad Cats can cause a lot of problems... If you have to have them get new ones(emissions bullcrap).. if not.. get rid of them and turn the code off(via a tune). and your IAT sensor probably just needs to be replaced... Simply fix..

[JoshieDoom]

Cool. If the dealer will do it for free that is always the way to go.

[matthewaqui]

Hey man,

Some on here also mentioned to me that the PCV may be clogged giving off the 430 code... you may want to keep that in mind for the fture since I noticed you have high numbers like me 150,000

Matthew

Cool. If the dealer will do it for free that is always the way to go.

[thopsramair]

I drive the M6 and have same problem except for I have no cats anyway. I was always wondering about this. Most of the time mine happens is after a really rough storm and it gets wet underneath. Strange to me.

[matthewaqui]

You luckout on this thread......... I have been advise to replace the IAT, the ECT and PCV Valve. That could possibly be our problem. The replacement to these parts are not very expensive.

Check these threads out to get a better understanding...... we seem to experience similar problems:


http://www.ls1.com/forums/showthread.php?t=79616

http://www.ls1.com/forums/showthread.php?t=70618

I drive the M6 and have same problem except for I have no cats anyway. I was always wondering about this. Most of the time mine happens is after a really rough storm and it gets wet underneath. Strange to me.