fearless

Ok guys, I am trying to figure out what happened to my vette when I hollowed out my cats. I have a Haynes book and am trying to pull my codes. I have a jumper going from A to B and the check engine light flashes like they said it would. My question is where do I look to find the number of code it is pulling up???? Will it display it by the check engine light or what???

jimg's'93

Hello Fearless and welcome to the forum!

I think you might find this link helpful:

http://www.corvettephotographs.com/c4vettes/codes.htm

I printed it out some time back and found it pretty helpful.

fearless

I appreciate that help, I had no idea what to look for. this is my first vette, My uncle gave it to me to restore and I am trying my hardest to get this thing back to the living again.

sami85L98

Fill out ur profile and what year we talking here? LT1's are different than L98, in my car 85 vette an L98 i hollowed cat many times had any code or SES light flashes, infact right now i completely removed cats, if u have an LT1 than it might be a different story as iam exp in LT1/4, best bet disconnect neg battery for a couple sec and restart this might clear codes from history, Hope some one chimes in for more info, but we need some more info about ur car what year, auto manual etc,.....

For some reaon i never see any codes display on dash when u jumped A B, but i have laptop and winaldl s/w, with Aldl cable i usually read error codes over there, but if u dont have any laptop or scanner take it a mech they might see what error code(s).

But what exactly is the problem?.

fearless

the problem is, I hollowed out the cats. Put everything back together and the car runs really rough. If it starts, it runs rough and if I try to give it gas, it will die. does not want to run at all. It is a 87 tpi coupe, auto tranny.

jimg's'93

Y'know, for what it's worth, hollowing out cats doesn't always give the expected. From some of the posts I've read, the throughput gained is minimal and your engine is expecting that backpressure. Guess it's a done deal now though. I will agree that you might try disconnecting the battery for 10-15 mins to clear any memory.

todd_vette

If this problem didn't exist before playing with the exhaust then it sounds like you caused a severe blockage while in there.
If it is nota new problem start with fuel check then spark at each plug... also check for fowled plugs.

fearless

ok I have a update. Battery was dead, so all codes where cleared now. I started the car and it ran rough for about 30 seconds. I tried to give it a little a gas and it died right away. Started it again and let it run without me giving it gas, and it died on its own after about 30 seconds. I tried to pull codes then after all this, and I am still not getting any codes, just code 12. What is the deal, all I did was remove passenger side manifold due to broken bolts, hollow out cats, put everything back, and now it don't run??????? Please help

Mr Mojo

What method did you use to hollow them out and why did you hollow them out? If the car was running fine, there is no reason to mess with it.

I don't have an L98, but I'm pretty sure there are two precats on the front Y pipe and then th emain cat in the center of the car. I think there is a front Y pipe without the precats available which would be better to use than hollowing out anything. Depending on how you did it, you may have debris clogging up the pipe, or maybe you broke a wire on one of the o2 sensors.

fearless

I think I may be buying the y pipe that eliminates the 2 pre cats and keeps the main cat in the middle and getting rid of my mufflers and putting muffler eliminators on it. But Could getting rid of the cats make my car do this crap?

jmeyer58

I would double check the wiring, did you pull plug wires to remove the manifold? Also as stated earlier, check the O2 wires. The ECM on that car is not smart enough to worry about if the cats are working. If all else is good I would agree with the clog downstream. Good Luck

fearless

I have checked to make sure all the plug wires are back were they are suppose to be. I have tried to start it and it just turns over. I did my jumper wire under the dash again to see if any new codes came up and nothing did, but while it was being jumpered, the car would at least start, but only run for about 30 seconds, still can't give it any gas with out it dying. It has a really strong gas smell from the exhaust, soo bad that you can't go out in the garage without stinking.

ozvette87

sorry i cant add anything of value, but im intrested to see what the problem is

Cross-FireKid

Could it be that you have a gas leak? I had one in my '84. The metal line under the car rusted through and gas was leaking. If there is a hole in the line it could suck in air and your car would not get enough fuel. Especially if you give it gas. Same thing happened to me. Good luck.

caa5030

Are you sure you removed all the pieces from the cat? I had a problem like this in my Iroc 5.7 TPI. There was still a piece of the honey comb wedged sideways against the exit of the cat. Your car will die if no exhaust is getting out.

RandyJ75

I think the problem may be that, if the battery is dead, and the alternator is not charging, that could be the reason that it dies. Remove he battery from the car, charge it up, put it back in the car, and then see what you have. Remember, jump starting a corvette is a bad idea, and the electical system is a bit different then most cars.

Good luck!

kalister1

Maybe the cats are clogged? Remove them and see if the car will run? If it does you know you have clogged them up instead of gutting them. If it does not, then you have eliminated one potential source of your problems.

jeffyc

just my 2 cents
if there was any thing left in the y pipe it might have cloged the main cat., and gutting the pre cats should not cause this problem

RWDsmoke

Check your fuel pressure. When my fuel pump failed the car would start and idle for a few seconds but die if I tried to rev it up. When you turn on the ignition switch (don't run the starter) you should be able to hear the fuel pump run for about two seconds then shut off again.

coupeguy2001

ok, let's start from square 1.
A. did it run fine b 4 you took the exhaust apart?
B. you said cats plural. you only have 1 cat.
c. If you hollowed out the precats rightbelow the firewall, take the y
pipe off, and start the car. if it runs, you screwed with the precats,
and they are plugged.
D. If you hollowed out the precats, how did you do it so that you knew
they were straight through since they are sandwiched between two
sections of curved pipe that you can't see to confirm?
E. Precats usually do not restrict flow enough to notice on a stocker.
F. don't screw with gutting cats, the stuff that comes out is hazardous
waste, and should be disposed of legally.