In need of some help???

[LTX_OUTLAW]

Hey guys needing some help the last few days my 93 formula hasn't been running quite right and this morning I was running about town and the engine light came on I stopped by the local parts store to get the codes pulled and It started with 3 code 12's then 3 code 63's around the time when the light comes on I usually driving about 55 or more and when I'm at a steady cruising speed It would be a great help if someone can point me in the right direction for the code 12 and code 63 thx

[jaysz2893]

DTC - 12 No distributor reference pulse (diagnostic test active)
#63 is right O2 sensor. The 12 means you are in diag mode and not really an error. I would say check wires to right O2 or replace it

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[LTX_OUTLAW]

i just asked a local parts store and they told me the code 12 is diagnostic test is working properly and the code 63 is one of the following map sensor signal voltage is high, small egr failure, right O2 sensor failure or cruise control problem

[bobdec]

Correct.. 12 code on a '93 says ECM is communicating OK.. the 63 says your Bank 2 (right, passenger) side O2 is not switching. Most likely bad O2, maybe burnt wires if you got headers..ECM will default to 'open loop'. With no O2 feedback and AFR correction could be why it's running a little off.
EDIT .. DTC 63 requires 158* engine temp, and 5% or above throttle for 60 seconds, so DTC only lights when running steady for a min or more..says O@ is stuck between 350 and 550 MV, normal voltage is 100-900 Mv swing.. so the O2 is acting lazy, not switching properly, but giving valid voltage readings, so no rich or lean DTC's are set. .

[LTX_OUTLAW]

I WENT TO A LOCAL SALVAGE YARD AND FOUND ANOTHER 93 FORMULA AND I PULLED THE MAP SENSOR AND INSTALLED IT AND TOOK THE CAR FOR A DRIVE AGAIN AND STILL THE ENGINE LIGHT COMES ON FROM THE LIST OF FAULTS FOR A CODE 63 MAP SENSOR SIGNAL VOLTAGE HIGH DOES THAT MEAN THE SENSOR IS BAD??? OR SMALL EGR FAILURE IS IT ON THE EARLY STAGES OF GOING OUT??? RIGHT O2 SENSOR FAILURE DUAL SENSOR ENGINE THATS KINDA SIMPLE TO UNDERSTAND AND THE FINAL ISSUE WITH THAT CODE 63 IS CRUISE CONTROL SYSTEM PROBLEM BUT THE CRUISE CONTROL WORKS FINE EVEN IN THE LOWER SPEEDS AND THE ENGINE LIGHT NEVER COMES ON IF SOMEONE CAN HELP OR PROVIDE ANY ADVISE IT WOULD BE A BIG HELP THX

[bobdec]

Think that MAP sensor being part of DTC 63 is for the older ODB1 SBC's. The LT1 only lists Right O2..

[jaysz2893]

Replace the o2 sensor. I have a 93 camaro and have had the same code. If you can swing it get delco ones. I have replaced too many Bosch ones.
Also local parts stores are usually off especially for 1993. Check shbox for the correct codes. It has saved me a lot of frustration
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[LTX_OUTLAW]

i just called local dealer to get a set of delco's and they even gave me a run around with the part#'s would anyone have the number for the left or right side's???

[meissen]

Dude no offense but you need to hold up your right hand and then use your left hand to get a hold of yourself. All along everyone's been saying that code 63 is right O2 sensor. Why'd you even waste time replacing the MAP sensor? There is no difference between right o2 and left o2 when it comes to part numbers. If you want to see if it's the sensor itself or the wiring going to it, swap the position of your o2 sensors... put the right o2 sensor in the left and vise versa. If the code changes to be left o2 sensor then you know the o2 sensor itself is bad. If it still says right o2 sensor, then your wiring going to the o2 sensor probably got fried somewhere against the header. Furthermore, don't waste your time buying them from a dealer just get them from your local NAPA or parts store...

[popo8]

Dude no offense but you need to hold up your right hand and then use your left hand to get a hold of yourself.
...

This line will come in handy till the day i die.

Ty for sharing it!!!


Larry (Popo8) Co-owner
LTXtech.com

[Alex94TAGT]

i just called local dealer to get a set of delco's and they even gave me a run around with the part#'s would anyone have the number for the left or right side's???

If your car is a 1993, then you should have non-heated oxygen sensors. I believe the AC Delco part number is AFS21 (same sensor used on either bank).

Cheapest place I've seen them is on Amazon.com. Run a search there for AFS21, and you should see a listing for $15.45 + free shipping. If they're old, I'd recommend that you go ahead and replace both at the same time.

Local autoparts stores carry an oxygen sensor socket for your 1/2"-drive socket wrench -- it's worth its weight in gold. My sensors sometimes don't want to break loose despite the anti-seize compound, so I have to heat them up with a propane torch before they'll budge.

[jaysz2893]

i took care of outlaw yesterday VIA pm.. i think he is on the right track now. For everyone else, DO 100% NOT believe Autozone, Advance Auto, NAPA, Dealer, buddy that fixes lawn mowers, the bum on the corner, or that other tech when it comes to our cars especially 1992-1993 ltx motors. These cars are getting old and parts are getting mistaken for the wrong ones. The local parts store has access to only thier inventory and how they catergorize things. I can not tell you how many times I had to just go with the correct part in hand or a good known part number to any parts store or my dealer to get the right parts. It is worse with my even older cars.. try finding a carb kit for a 1963 corvair with a factory turbo. How I led LTX_OUTLAW down the right path was some simple google searches and using shboxes site..I dunno how many times that simple combination of 2 actions has saved my ass with my camaro. Also I feel that we are a great community and the is A LOT of knowledge here. PLEASE try to believe most of what peolpe here are telling you. Many of us have been doing these motrs for a long time. My car may not be a 700HP monster but I have personally touched every part of the damn thing in the past 11 years and know what a lot of ppl are going through. Sometimes i feel like my comments as well as others here fall on deaf ears becasue it is not the answer the OP was hoping for or expecting. These cars are frustrating but not impossible. With a litte educated guessing, good question asking / answering, good listening skills, an open mind, and the ability to live through the frustration you can and will solve the LTx issues. /rant