I have had these since I switched to the pacesetters months ago. I thought they were the rear 02s. the tuner said something about the 05s...anyway, I finally had them checked to see that the codes were and they are P0420 and P0430, which are Catalyst System Efficiency Below Threshold (Bank 1) and Catalyst System Low Efficiency Bank 2, respectively.

Are these the fronts or rears? If it is the fronts, would the anti-seize I put on the threads be the cause or something else?

 

Catalyst system effeciency codes are refering to the rear O2's since they're the ones responsible for checking the catalytic converters. I'd suggest getting your tuner to turn off those SES codes or use O2 sims.

 

sweet, that's what I thought. the codes are supposed to be turned off...or at least, my tuner said he did but he also said something about the 05s being pesky. I am going to talk to Allen Nelson and see what he says about it since my tuner has not done near the number of trucks Allen has.

 

BLK03 who is doing your tunes where are you located at. if you are near McAllen Area talk to TIBURON he knows his tunings on 99-06 gm trucks he re-tune mine and what a DIFFRENCE or EDGAR at AGGRESSIVE MOTORSPORTS

2004 Chevy LS
RC/SB
LM7 5.3L
4l65E w/SHIFTKIT,VETTE SERVO
2200 TQ Converter OEM unit reflash
G80 w/3.73

ADD ons: LS1 electric Fans,TB bypass, TB spacer, 160* Thermostast, MAC Cold air induction, Borla ProXcess Muffler w/Tailpipes and no cats, NitrousWorks 150 shot, HP Tuners Tune, 295/50r16 BF GOODRICH radials.

Future Mods 6.0L, patriot 5.3L Stage 2 head and cam kit, Vigilante 3000 stall, 4.10 gears Longtubes and OFY pipe, TNT N2O set up.

Team/ NLHP Engine Works

 

south of houston. the tuning was done at g-force over in pearland.

 

If you ever go to the valley give TIBURON an email he will get you going....

2004 Chevy LS
RC/SB
LM7 5.3L
4l65E w/SHIFTKIT,VETTE SERVO
2200 TQ Converter OEM unit reflash
G80 w/3.73

ADD ons: LS1 electric Fans,TB bypass, TB spacer, 160* Thermostast, MAC Cold air induction, Borla ProXcess Muffler w/Tailpipes and no cats, NitrousWorks 150 shot, HP Tuners Tune, 295/50r16 BF GOODRICH radials.

Future Mods 6.0L, patriot 5.3L Stage 2 head and cam kit, Vigilante 3000 stall, 4.10 gears Longtubes and OFY pipe, TNT N2O set up.

Team/ NLHP Engine Works

 

who did your tuning initially, what color is your truck?

 

I have these two codes P0420 & P0430 Catalyst System Efficiency below threshold bank 1 & 2....That's the reading I got from the emissions test results on my 1999 Chevy Tahoe LT...can y'all please tell me the meaning of the code is?

 

Your cats are bad or missing.

 

cats??? whats that...sorry for asking so much.