06 4.7 D.C. TROUBLE CODE HELP

the truck is an 06 DC with the 4.7. she has 245k and new to me. guy said when i bought it it needed a cat cel was and is on. i put a starter in her ( lota fun there) on reinstalling the intake i snapped the rear right side bolt and did not repair it. sprayed all around it with carb cleaner and no idle change also no audible vac. leak. i ran a scan the other day and she's throwing multiple codes they are, P0430Catalyst System Efficiency Below Threshold (Bank 2 , P0121Throttle/Pedal Position Sensor “A” Circuit Range/Performance Problem. , P0123 Throttle Pedal Position Sensor/Switch (TPS) A Circuit High Input, and P2135 "Throttle/Pedal Position Sensor/Switch A / B Voltage Correlation. the p0430 is my bank 2 downstream O2 sensor. has anybody experienced these 4 at the same time and if so what was your fix? when putting my TB back on after the starter swap i broke the tabs on the electrical connector clip where it plugs into the tb but it's still on nice and tight. also lost the small red rubber seal that is in same tb connector. Now ever since I've had the truck on cold or even warm start ups, she idles at 1200 rpm's initially with the fan on then the fan cuts out but the high idle remains for 3 to 4 minutes, after that all is good except for a little stumble when accelerating from a stop. once initial high idle settles down she purrs like a kitten, no stumble, shaking, Nada. i have a decent live data scanner but don't have the hang of it yet also a good volt/ohm meter that I'm also learning. hep me, hep me, somebody hep me. lol

 

First off, make sure you're using OEM (Denso or Aisin) parts on the electronics. Especially the starter and O2 sensors. You can get away with Magnaflow cats, but lots of guys have had CEL issues with other brands. For the starter, your original lasted 240k+ miles, you do not want non-OEM unless you want to be doing this work again in 20k, 30k, 50k miles or less. OEM is built to last, it's why it costs more, and a reman OEM starter will definitely last you at least another 100k. And do not buy your parts online at major outlets like scAmazon, fleaBay, WallyMart, it's counterfeit-parts-central.

P0430 suggests of a bad cat, not bad O2 sensor necessarily, but the PO told you about the bad cat already. If you wanted to replace both O2 sensors on passenger side because 'why the hell not', go for it. Be sure to buy Denso O2s.

The fact you had the intake manifold off, and the throttle assembly and its wiring was probably dicked around with, and you're now getting codes related to:

• P0121 / TPPS voltage, circuitry, or wiring
• P0123 / TPPS voltage, circuitry, or wiring
• P2135 / TPPS voltage, circuitry or wiring

Should be no surprise to anyone-- these are all basically in the same wiring bucket, and purpose-wise: You dicked around with the wiring and/or throttle body assembly while replacing the starter. I'd be double-checking my wiring, making sure you didn't pinch or damage anything, unseating/reseating all connectors on/around the throttle body assembly. Then clearing codes and starting over.

I really hope you replaced the starter for a good reason, and not 'just because'. Not saying it's unheard of for OEM starters to go bad on these trucks, but some guys have quite a bit more mileage than you and still haven't had to change theirs. Others only changed because mice got under the intake and chewed up wiring.

 

the truck started giving me intermittent no starts. i did the usual steps in diagnosing it and it was in fact the starter that was bad and yes, i bought a reman denso unit from rock auto for 98 bucks for the cold weather version. i also bought all 4 denso O2 sensors. I'm thinking the cats are aftermarket reason being both downstream sensors are plugged into the cats themselves, not south of them as i think the factory set up was. Maybe you can chime in on that. NOW, I was just outside messing with the scanner. i cleared all codes, started the truck and let it run for about an hour and from time to time brought her up to 2500 or so R.P.M.'s several times. scanned her again and all codes are gone. shut the truck down, restarted and let her run for another half hour then scanned again. still no codes. what are the chances they will return after some driving? I'm ok at keeping the pre emission era stuff going. my 87 jeep comanche has 268k on her 4 angry squirrels, my 87 e30 (white) 235k, and the real love of my life, my 1986 325es e30 with 415k on the clock. man are those e30's fun to drive. this emission crap throws my brain into limp mode. thanks again, I'm sure I'll be back.

 

OEM setup on most vehicles is normally on the tube before and after the cat, not on the canister of the cat itself. It's supposed to be measuring before combustion enters the lattice/honeycomb inside the canister, then again after it comes out.

But really, aftermarket cats have caused ample problems for others here. The Summit Racing performance cats, the Magnaflow cats, OEM cats are about the only ones people have found that don't throw codes per purchases so far.

Likely, but sometimes stuff takes time to settle in. If it's electrical in nature, you never know. I recommend to re-check all grounds you can find in the engine bay, just in case one is loose and contributing to the issue. Double-check your cables to the battery too.

Emissions is a bear. I don't always understand it. Especially aggravating when you get into the EVAP shit. I preferred my '70 Impala and '68 C10. The C10 specifically ... like 4 wires between the cab and firewall to make the engine start and run. Shitty ass gas mileage, half what my Tundra gets (until the LS1 swap) but the art of simplicity, I loved every bit of it.

 

Oh - and consider new cats

You don't need to splurge on OEM necessarily. I'm pretty sure the OEM are all on national backorder right now anyway.