CamaroFan71

iTrader: (2)

P0171 Fuel trim bank one condition...
Says probable causes are..
1- If bank one and two codes are set together suspect fuel pressure or MAF sensor
2- O2 defective (supposed to be new)
3- Ignition misfire-repair
4- Fuel injector problem

P0420 Catalyst efficiency low-bank 1
probable causes are..
1- Catalyst converter defective (failure possibly due to #2, #3, or #4)
2- Engine misfire or running condition
3- Large vacuum leak
4- Engine oil leakage into exhaust-valve guide seals,piston rings

P0174 Fuel trim bank 2 condition
probable causes are...
1- Bank 1 and 2 suspect furl condition or MAF sensor
2- Failed HO2S21
3- Ignition misfire condition
4- Fuel injector problem
5- Engine mechanical condition

The car runs like a new car, but when this **** kicks in it wont hardly rev past 4K and gets all jerky and ****

01 SS M6 113k miles. Any ideas guys??

samson_420

iTrader: (1)

You got me stumped, I would like to see if anyone alse will actualy know.

Formula413

iTrader: (1)

I would start by checking fuel pressure and checking for vacuum leaks.

Black98T/A

iTrader: (5)

I'm getting the exact 3 codes on my 98, did you ever fix it?

LS6427

iTrader: (2)

bad 02 sensors can do all of that. When my 02 wires were burnt because some clown did some tranny work and when he put everything back together he let the 02 sensor wires lean up against my LT's. Thats what my car did.

Black98T/A

iTrader: (5)

well I checked the O2's...no burnt wires. CAr has 130k on it but O2's aren't cheap...should I just replace the 2 front ones for good measure? It costs me $60 for an engine diagnostic.

Black98T/A

iTrader: (5)

I also swapped MAF with a spare one I have, SES light is still on.

linegtdt52

iTrader: (12)

I have the same P0171 code so I am gonna swap fuel injectors and put good wires on the car and see what happens. I have been dealing with this bullshit far too long.

wrencher

iTrader: (2)

I would concentrate on the 171/174 codes first. That is the sytem is lean per the O2 sensor input & the fuel trim #'s are in the high to compensate for this.
The fuel trim #'s are what flag this code.
The fuel pressure, the maf vacuum leaks all can set these codes.

This is where a scan tool or data logger can help immensely to help diagnose these problems. you need to know where the fuel trims are high, ie @ idle or cruise & it will help you narrow it down.

As for the catalyst inefficiency code, not unheard of for the cats to go bad. there was even a warranty extension from GM for the 2K & up f-bodies for this problem.
But it cannot be dealt with till the fuel trim codes are remedied first.

Black98T/A

iTrader: (5)

I was hoping the problem was a bad pcv valve hose/connection...I replaced the valve and hose, reset PCM...all 3 codes are still there!

What to do next?

Formula413

iTrader: (1)

Did you try checking for vacuum leaks by spraying carb cleaner on and around all vacuum sources?

RsSean

iTrader: (27)

Yes I would say vaccuam lines. Use A carb cleaner or brake cleaner spary around the vaccaum line, if you have a leak the idle of the car will change, normally try to die. I can find you a step by step instrutions for all three of those codes if you would like I have the owners manuals. Normally start with the lower number code first. if that helps.
How are you pulling those codes? If possible you can watch a graph for every cylinder for misses too.

Black98T/A

iTrader: (5)

The SES light went out yesterday for about 50 miles...it came back on today.

The car idles and runs no different than when I first bought it without the light coming on.

Black98T/A

iTrader: (5)

any help appreciated before I spend $70 for a diagnostic.

Black98T/A

iTrader: (5)

Any help before I take it in this week?

ROCNDAV

iTrader: (100)

Did you ever find out what your problem was?

nighthawk15

Man if you figure it out let us know. I have the 171 and 174. I'm hoping when I put on new O2s + plugs and wires with my LTs that they'll go away.

Black98T/A

iTrader: (5)

Nope...the problem originally sprung up right after I took it to the dyno tune shop for another problem(I fixed) Don't know if there's anything they could have done to cause it but my last resort is to take it back to them.

Black98T/A

iTrader: (5)

well I took it to the shop for a diagnosis($63) The pcv breather tube hose at the rear of the engine(part # 12560692) is corroded and cracked and setting the codes!

A common problem I've heard...so far the local pontiac dealer has it for a ridiculous $136...I'm shoppin around though.

ROCNDAV

iTrader: (100)

THere was a thread on here, I cant find it at the moment, that showed how to use this to fix that broken line problem:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=140300114275

Do you have a pic of the hose that broke?