Power loss and red hot catalytic converter


Teile
08-28-2007, 01:36 AM
Last week on my way home I noticed that I wasent getting as much power in when accelerating. When I got home I heard a crackling sound under my car so I took a look and my catalytic converter was glowing red, So I took it down to the muffler shop and had the guy there take a look and he said that my car was running rich and that I would also need a new catalytic converter. I tried to get them to do a read out but they said they were unable to due to the fact that my car was a 93 and their shop does 96 chips and above and aparently all the other autoshops in town can't either. So based on the power loss and the catalytic converter being out what is the most probable cause for my car to be running rich.

trooperbc
08-28-2007, 02:44 AM
Last week on my way home I noticed that I wasent getting as much power in when accelerating. When I got home I heard a crackling sound under my car so I took a look and my catalytic converter was glowing red, So I took it down to the muffler shop and had the guy there take a look and he said that my car was running rich and that I would also need a new catalytic converter. I tried to get them to do a read out but they said they were unable to due to the fact that my car was a 93 and their shop does 96 chips and above and aparently all the other autoshops in town can't either. So based on the power loss and the catalytic converter being out what is the most probable cause for my car to be running rich. yes that is the most likely cause for the cat being so hot, it is working overtime to convert that extra stuff, and you may or may not need a new cat converter, depending on how long this has been going on.

the most likely cause is a miss, and the most lilkely cause(s) are the ignition (sparkplug) wires are shorting out because oil has gotten in the sparkplug tube, a common problem, and it is shorting out the plug. it is also possible, the connector has become loose because of the oil and is seperated from the sparkplug, causing the miss.
you can replace the rubber seals that keep the oil out, if that is your problem, but you have to remove the valve cover to do it, they install in the valve cover.
you can replace your stock ignition wire set with the 'new' set that isuzu came out with for this problem that have larger diameter connectors with ridges that are designed to keep the oil out away from the spark plug (they came up with that brilliant idea so they didn't have to replace all those vc sparkplug seals under warranty).

it is also possible, even likely, that you have a miss because of one or more ignition coils (you have 3, 1 for a pair of cylinders). you can troubleshoot that and if two cylinders aren't firing properly and they are powered by the same coil, you have found your problem. you can replace the coils seperately or you can buy the whole coil/ignition module as a unit. it is also possible, that the ignition module, which sits below the coils, is the problem.

but i bet on either the oil in the tube(s), igniition wire problems, and/or the distributorless ignition coil(s).

and of course there is the possibility a sparkplug is the problem, either orignially, or as a result of the misfiring.

hth

//bc

trooperbc
08-28-2007, 02:47 AM
and btw, you have the OBDI diagnostics system CEL, so you can read your own codes by jumpering the connector and reading the flashes of the Check Engine Light. this problem may or may not have set a code -- it didn't with me.

//bc

Teile
08-28-2007, 03:53 AM
Ok so I wouldn't need tool? I can just read the flashes to get the code I need to figure out whats causing my issue? Sorry if I sound stupid but i'm not really a car repair person but don't mind getting ym hands dirty.

Teile
08-28-2007, 07:27 AM
Im having a little trouble finding the connector its behind the drivers side kick panel correct?

Teile
08-28-2007, 08:27 AM
Well finally found the connector and used a paper click to make the connection. I kept just getting the standard 12. No other codes.

Cat Fuzz
08-28-2007, 09:35 AM
Code 12 is the standard 'no codes' code. I would probably start with a good tune-up. Spark plugs and wires. Borg Warner now makes the wires with the little raised lip to keep oil away from the plugs. Check Parts America .com for a good price on those. Be careful changing the plugs, only when the engine is cold and use anti-seize on the threads and gap them properly. The heads are aluminum so be very careful not to cross-thread them.

A neat thing to try is to buy six cheapy in-line spark testers at Harbor Freight and you can visually see the spark on each cylinder.

Teile
09-04-2007, 11:00 AM
K ive checked the cel again and this time I recived code 11 and 13. What do these codes mean?

95.5 Rodeo
09-04-2007, 11:52 AM
K ive checked the cel again and this time I recived code 11 and 13. What do these codes mean?

I have looked and not found anything about a code 11, you may have miscounted the flashes.

However, there is a code 13:

http://www.extreme-check-engine-light-codes.com/Isuzu%20OBD1%20Decoder.htm

It indicates a problem in the oxygen sensor or it's circuit. When this happens the engine will not go "closed loop".

FWIW, I had a friend who owned a Toyota with the same red hot catalytic converter trouble. He replaced the oxygen sensor and it fixed the problem.


Good luck,
Dale

Teile
09-05-2007, 12:59 AM
So is it hard to replace the oxygen sensor? Where is it located?

trooperbc
09-06-2007, 11:43 PM
So is it hard to replace the oxygen sensor? Where is it located? it's on the exhaust prior to the cat converter. since you don't have a manual (at least get a haynes or chiltons from a bigboxpartsstore or library, or pay good$ for the factory service manual www.helminc.com (http://www.helminc.com)) ...since you don't have a manual a good resource for you will be the isuzu online parts site www.myisuzuparts.com (http://www.myisuzuparts.com) for their totally complete parts illustrations.

replacing the O2sensor is easy. you may want to get the special O2 sensor socket. the biggest trick to know is don't do it when the exhaust is cold or very hot. warm it up, and then start to work on it and the hole will have expanded a bit to allow the thing to turn out. when cold it's 'bout impossible.

//bc

Teile
09-07-2007, 01:25 PM
OK i have replaced the catalytic converter and the oxygen sensor took it out for a quick spin and im still having the same problem. What else can I check.

Teile
09-07-2007, 01:33 PM
I should also mention that I have gotten the power back in my car but I don't think it will stay unless i find whats causing the problem.

FL 3.2L
09-07-2007, 02:03 PM
Have you pulled the plugs to see if you can find a cylinder that's not firing properly?

Teile
09-07-2007, 02:07 PM
Actually I just came back in from doing that. Their all firing properly.

Teile
09-07-2007, 02:23 PM
I was reading up on some probable causes to the problem and came across coolant tempature sensor could this cause my converter to glow red?

95.5 Rodeo
09-07-2007, 03:44 PM
OK i have replaced the catalytic converter and the oxygen sensor took it out for a quick spin and im still having the same problem. What else can I check.

Did you or someone else reset the computer after the oxygen sensor was replaced?

This was my experience:

http://www.automotiveforums.com/vbulletin/showthread.php?t=258045

im still having the same problem. What else can I check.

I assume that the converter still getting red hot, is this the case?

I was reading up on some probable causes to the problem and came across coolant tempature sensor could this cause my converter to glow red?

If the coolant temperature sensor is out of range, the computer should set a code 14.

Have you checked for any new codes?

You may want to inspect the fuel pressure regulator. It is very easy to do. When the diaphragm goes bad, raw gas is dumped into the intake manifold. Remove the vacuum line from the regulator and look for any sign of gasoline in the hose.


Good Luck,
Dale

Teile
09-07-2007, 04:04 PM
I just tried to get more codes and it comes back with nothing but the standard 12. Im at a loss.

Teile
09-07-2007, 07:12 PM
Yes the new converter is getting red hot. I'm replacing the spark plugs right now just for the hell of it. Might even do the wires too, not sure if they really need it but least with them replaced i can rule them out completely.

95.5 Rodeo
09-07-2007, 08:51 PM
Yes the new converter is getting red hot. I'm replacing the spark plugs right now just for the hell of it. Might even do the wires too, not sure if they really need it but least with them replaced i can rule them out completely.

Did you reset the computer or check the fuel pressure regulator as I have suggested?

What did the spark plugs look like? Sooty black I'd guess....

FWIW, If all the spark plugs look the same, I wouldn't spend the time or money on wires, the problem is elsewhere.

FL 3.2L
09-08-2007, 12:51 AM
Actually I just came back in from doing that. Their all firing properly.

Then why are you replacing the plugs and wires?

Teile
09-08-2007, 10:26 AM
I replaced them because it was about time to do it anyways. Been almost 2 years since the last time a replaced them. Ill be checking the fuel pressure regulator today.

Teile
09-08-2007, 02:20 PM
Well looks like the only plug I was unable to get to was the problem. I changed out all my spark plugs and the wire and the problem has gone away. Thank you all for your help. Its was greatly appreciated.

trooperbc
09-08-2007, 02:25 PM
Well looks like the only plug I was unable to get to was the problem. I changed out all my spark plugs and the wire and the problem has gone away. Thank you all for your help. Its was greatly appreciated.what plug was that, and what condition was it in?

thanks


//bc

FL 3.2L
09-08-2007, 05:11 PM
My money is on #6.

FL 3.2L
09-08-2007, 05:11 PM
And glad you got it!

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