98 ram 1500 4wd with 5.9 check engine light flashes 27 times ....is this the code for bad o2 sensor or cat ?

[RaJeana]

Have a 98 Ram 1500 half ton 4wd with a 5.9 automatic. Under acceleration it has started flashing the check engine light 27 times . I don't think it will make it back home if i try to take it to town to get it scanned. It dies when first put in drive if you don't give it extra gas idle is rough . Exhaust still blowing seemingly normal but smells different actually no smell now used to smell but not like fuel . Cat doesn't seem to be overly hot but muffler does have alot of rust damage . I can't flip the key to get it to throw the code because it hangs so I'm having to count this while driving . I can't find a definite answer as to which code this stands for but i believe o2 sensor if so is there anyway to tell if its upstream or downstream ? Does it have 2 upstream if so should i replace both ?

 

[Yeret]

Flashing CEL is usually, from what I understand, a severe misfire in at least one cylinder, which causes a bunch of unburned gas to get sent through the exhaust. This can ignite upon hitting the catalytic converter, which will damage it if it happens. I've encountered this twice over the years.

First time was a result of a blown plenum gasket, which caused oil to get drawn into the intake charge. This caused numerous problems, but getting heavy on the accelerator would sometimes cause a blinking CEL due to fouled spark plugs failing to fire.

Second time was an odd one. It would suddenly start flashing if I turned O/D off and went heavy on the accelerator while going up steep hills. What made it odd was I didn't actually feel anything wrong with the engine, no loss of power, shaking, or anything. I ended up replacing the ignition coil on a whim and the problem never occurred since. The old coil ohm'd fine, but I suspect it might have lost more than acceptable resistance when it got hot, resulting in a misfire (I guess?) under load. Not 100% on that one, but all I can say is a new coil did fix it.

 

[GTyankee]

video shows simple trick to reading your Rams Codes
2001 Dodge Ram works exactly like your 1998 does

How to Read Dodge Truck Check Engine Codes Without a Scan Tool

In this video, I quickly demonstrate how to view a Dodge truck OBDII code related to a check engine light without having a scan tool. The code will flash up...

www.youtube.com

 

[GTyankee]

This blinking light usually indicates a severe engine misfire allowing unburned fuel to be dumped into the exhaust system. There it can quickly raise the temperature of the catalytic converter to a point where damage is likely, requiring an expensive repair.

Why is my car shaking and the check engine light flashing?


A blinking Check Engine light means there's something seriously wrong with the emissions system. The shaking suggests you're having a misfire, which is dumping unburnt fuel into the exhaust, while making the engine shake. This is usually caused by a bad spark plug, ignition coil, or wiring.

 

[RaJeana]

Flashing CEL is usually, from what I understand, a severe misfire in at least one cylinder, which causes a bunch of unburned gas to get sent through the exhaust. This can ignite upon hitting the catalytic converter, which will damage it if it happens. I've encountered this twice over the years.

First time was a result of a blown plenum gasket, which caused oil to get drawn into the intake charge. This caused numerous problems, but getting heavy on the accelerator would sometimes cause a blinking CEL due to fouled spark plugs failing to fire.

Second time was an odd one. It would suddenly start flashing if I turned O/D off and went heavy on the accelerator while going up steep hills. What made it odd was I didn't actually feel anything wrong with the engine, no loss of power, shaking, or anything. I ended up replacing the ignition coil on a whim and the problem never occurred since. The old coil ohm'd fine, but I suspect it might have lost more than acceptable resistance when it got hot, resulting in a misfire (I guess?) under load. Not 100% on that one, but all I can say is a new coil did fix it.

Flashing CEL is usually, from what I understand, a severe misfire in at least one cylinder, which causes a bunch of unburned gas to get sent through the exhaust. This can ignite upon hitting the catalytic converter, which will damage it if it happens. I've encountered this twice over the years.

First time was a result of a blown plenum gasket, which caused oil to get drawn into the intake charge. This caused numerous problems, but getting heavy on the accelerator would sometimes cause a blinking CEL due to fouled spark plugs failing to fire.

Second time was an odd one. It would suddenly start flashing if I turned O/D off and went heavy on the accelerator while going up steep hills. What made it odd was I didn't actually feel anything wrong with the engine, no loss of power, shaking, or anything. I ended up replacing the ignition coil on a whim and the problem never occurred since. The old coil ohm'd fine, but I suspect it might have lost more than acceptable resistance when it got hot, resulting in a misfire (I guess?) under load. Not 100% on that one, but all I can say is a new coil did fix it.

 

[RaJeana]

I could do that on my other truck but the ignition has a spot where the key hangs on the way back off cant get it not to .