Here's the text of a post I recently put up on another forum without any real help....

Last summer, it started cutting out really bad when I did anything to heat up the engine bay. That is to say, the truck wasn't running hot but if I idled on hot asphalt for example or did alot of stop and go on a hot day, the problem would surface. It should be noted that I do have headers on the truck so the engine bay heats up more than it would with the stock logs on there, I'm sure. However, the headers have been on the thing since 99 or 2000 without a prob. I chased all the obvious stuff; put new plug wires, plugs etc to no avail. The prob persisted for a couple of months until it finally lit up the check engine light. I took it to the shop to where I was told the oxygen sensor was bad. I went to the dealership and purchased an OEM brand new O2 sensor and installed it. Walla!!! The problem went away for the rest of the summer and through the winter.

The bad news: for the last several weeks it's been doing the same freakin' thing again. It acted EXACTLY the same this time as last even the part where it took several weeks to light up the light. Obviously, I suspect I got a bunk sensor. I'm gonna bite the bullet and go pick up an OBDII code reader today and pull the code. I would almost bet money it's gonna say bad O2 sensor again. My question is, assuming it does indicate the sensor is bad, are there any other probs anyone knows about that could cause this reading falsely? I hate to keep throwin money buying 02 sensors if it's something else. Could there be anything else wrong causing the sensor to fail prematurely? My plugs looked great when I pulled them.

Also worthy of note: The truck is equpped with a Jacobs Pro-Street capacitive discharge system, K&N filtercharger (the old style), the a fore mentioned headers, and the stock muffler has been swapped for a 70 series flowmaster. That's it for mods.

UPDATE: I have since gone and picked up a code reader which now tells me there are no codes stored. This is impossible with the check engine light lit on an OBDII vehicle, right? I sure would like to verify the damn problem before I through too much money at it.

Do any of you dodge boys have any suggestions as to how to proceed or what I might be missing?

First, take your POS code reader back, and get your money back. No its not impossible for that to happen when using a cheap code reader, there is a reason shops and tech.s pay upwards of $5,000 for a scan tool, it does alot more than dispaly a DTC. The scan tool a shop uses will be able to show them O2 sensor readings and they will be able determine from that, not a DTC, whether or not you have a bad O2 sensor. My advice, pay the shop to fix it, or just throw a sensor at it.

Thanks. I'm leaning the direction of just throwing another sensor at it since my overpriced local wrenches will charge me damn near what the part costs to tell me it's bad. As a bit of a computer nut, it just seems to me like pulling a 5 character piece of text out of memory shouldn't require 5k dollars worth of gear. Guess that makes me a dumb redneck!

I'm told there is a way to do it by turning the key back and forth too. Anyone know if this is the case? I was under the impression that only worked on the older OBD.

http://www.genisysotc.com/
does a hell of a lot more than pull a code, go there and check it out. You can use it to do all kinds of stuff, heck some cars you can roll the windows up and down with one. You could also ask the shops to just "read" the DTC most don't charge for this and they will simply tell you the code number and description and thats it.(sorry for not mentioning that sooner)

The key switch trick worked on OBD II vehicles as well, but not all of them. I believe that the '98 rams were one of the vehicles that it doesn't work on, but I don't know for sure because I've never personally owned a '98 or really had to work on one too much.

As far as your truck goes, I would almost say that it sounds like an EGR problem, but the newer trucks like yours didn't have EGR (at least the federal emissions equipped ones - not sure if CA was different) so this is not a problem. One thing I would consider checking (if an o2 sensor doesn't fix it) would be the ignition system. You mentioned that it had a jacobs ignition system on it. I would think that the ignition coil may be suspect (or the box itself) in a situation like this as well.

First, take your POS code reader back, and get your money back. No its not impossible for that to happen when using a cheap code reader, there is a reason shops and tech.s pay upwards of $5,000 for a scan tool, it does alot more than dispaly a DTC. The scan tool a shop uses will be able to show them O2 sensor readings and they will be able determine from that, not a DTC, whether or not you have a bad O2 sensor. My advice, pay the shop to fix it, or just throw a sensor at it.
5,000? I wish! We have almost 12k into ours at is sits now.
Okay, here come the hard part, you prob cant fix your turck yourself without the scna tool and lots of experiance. Now thats over heres a small list of what I have seen with problems like this: The k and n air filter put oil onto your mass air flow sensor causing it to read eraticly thinking its an o2 sensor problem. Bad o2 sensors. Bad connections at the o2 sensor or mass air flow sensor. Bad PCM. Bad PCM connection. Ok thats just getting started. You have to have the proper scan tool to check out everything indivudually and then toghether dynamicly to see how the relationships are working out. If somthing is bad(lets say MAF), then it makes the o2 sensors go haywire setting a code. It is what I do everyday, and went to alot of school to learn. my .2

Edit:Also the aftermarket ignition system might be a problem. It could be doing a thousand things, but I am not familer with that perticular system.
And Genisis sytems are sweet! I am going to buy one after I get out of college this time around. Our Strap-on system is VERY unreliable, while the Genisis sytem is the same thing for a third the price and more reliable. Everyshop should have one as a backup, if not the main scanner IMO.

5,000? I wish! We have almost 12k into ours at is sits now.
Okay, here come the hard part, you prob cant fix your turck yourself without the scna tool and lots of experiance. Now thats over heres a small list of what I have seen with problems like this: The k and n air filter put oil onto your mass air flow sensor causing it to read eraticly thinking its an o2 sensor problem. Bad o2 sensors. Bad connections at the o2 sensor or mass air flow sensor. Bad PCM. Bad PCM connection. Ok thats just getting started. You have to have the proper scan tool to check out everything indivudually and then toghether dynamicly to see how the relationships are working out. If somthing is bad(lets say MAF), then it makes the o2 sensors go haywire setting a code. It is what I do everyday, and went to alot of school to learn. my .2

Edit:Also the aftermarket ignition system might be a problem. It could be doing a thousand things, but I am not familer with that perticular system.
And Genisis sytems are sweet! I am going to buy one after I get out of college this time around. Our Strap-on system is VERY unreliable, while the Genisis sytem is the same thing for a third the price and more reliable. Everyshop should have one as a backup, if not the main scanner IMO.

Too bad these are speed density EFI, not MAF. You won't find an airflow meter on a '98 ram so don't bother looking for one.

5,000? I wish! We have almost 12k into ours at is sits now.
Okay, here come the hard part, you prob cant fix your turck yourself without the scna tool and lots of experiance. Now thats over heres a small list of what I have seen with problems like this: The k and n air filter put oil onto your mass air flow sensor causing it to read eraticly thinking its an o2 sensor problem. Bad o2 sensors. Bad connections at the o2 sensor or mass air flow sensor. Bad PCM. Bad PCM connection. Ok thats just getting started. You have to have the proper scan tool to check out everything indivudually and then toghether dynamicly to see how the relationships are working out. If somthing is bad(lets say MAF), then it makes the o2 sensors go haywire setting a code. It is what I do everyday, and went to alot of school to learn. my .2

I know 5k was lowballin it but if you have some connections a otc genisys ain't that far from 5k minus a scope and 5 gas. Anyway I do agree with you on the importiantce of proper diag. just seems like it may be a repedative problem worthy of the "parts shotgun".

Too bad these are speed density EFI, not MAF. You won't find an airflow meter on a '98 ram so don't bother looking for one.
Sorry, I was being genaric. I was thinking chevy and subaru systems where is kills the maf pretty fast. Andwho, the k&n oil messed up alot of stuff on certian systems. My bad. I made a mistake:eek:. not the first time...nor the last:D !

Sorry, I was being genaric. I was thinking chevy and subaru systems where is kills the maf pretty fast. Andwho, the k&n oil messed up alot of stuff on certian systems. My bad. I made a mistake:eek:. not the first time...nor the last:D !

It's not a big deal, I just thought I would clarify a little for this guy who may go looking for one on his truck.

BTW - I could see K&N oil messing up a hot wire MAF fairly quickly but I've never seen a Karmann MAF messed up by it. I'm not saying it won't, but that may be something to log in the back of your head if you ever work on one of those systems.

I am just familer with the hot wire types. What is the other system? Isnt it an old MAF system type? The name doesnt sound familer, but we work on chevys and subarus all day long, and the four letter words(F**d's). But we dont count the last one, its a given:laughing:.

I am just familer with the hot wire types. What is the other system? Isnt it an old MAF system type? The name doesnt sound familer, but we work on chevys and subarus all day long, and the four letter words(F**d's). But we dont count the last one, its a given:laughing:.


The Karmann systems aren't as common as the hot wire and flapper type systems, but they are around. Mitsubishi has used the Karmann systems quite extensively over the years, with the Lancer EVO being a current model with it (not sure what other models may currently use it though). Basically what the Karmann system does is measure the amount of air vortecies (sp?) that are going through the MAF at any given point in time and transmits the data to the ECU in the form of a frequency. It seems like it works pretty well but you have to make sure the screen in the airflow meter is not removed or else it will run like crap. Sorry for taking this thread way off topic! :flipoff2:

It's not a big deal, I just thought I would clarify a little for this guy who may go looking for one on his truck.

BTW - I could see K&N oil messing up a hot wire MAF fairly quickly but I've never seen a Karmann MAF messed up by it. I'm not saying it won't, but that may be something to log in the back of your head if you ever work on one of those systems.LOL...I was already planning on clarifying that myself. I'm aware my system is speed density. Thanks though.

The good news is that I got Kragen to take back that reader even though the sales guy balked at the idea at first.

The only reason I'm not in a real big hurry to take it to the shop is the fact that I went to the best shop in town when the problem first happened last year. They hit me with 90 bucks to tell me that it was indeed an O2 sensor. Now the truck is acting EXACTLY like it did then. This coupled with the fact that I've had any number of folks tell me that these sensors are notorious for being bad right out of the box. This weekend I'm gonna take a good look at the connections and wires on it and if they look ok I'll bite the bullet for another sensor. If that doesn't work....

http://www.theleeworld.com/MySpace/dynamite.gif

Actron makes a $200 scanner that will read and clear DTC codes as well as read live data from the computer. It will give O2 status and voltages as one of the outputs. It will map the 99 standard sensor outputs when they are available.

this is the one I have http://www.actron.com/product_detail.php?pid=16150

picked it up new from amazon for $199

btw, i have had good luck with the bosch sensors. the lastest set i put in (new motor) were their universal 4-wire heated types. once i figuered out the wiring color mathces they were simple. working great so far.

The only sensors we install are Bosch, Delco, or NTK. A bigger question, what was the actual code? Was is a o2 heater fault? Was it a o2 voltage high code? Or voltage low? Mabye a o2 no switching? Also which o2 sensor is it? All these things tell us more about the problem.

I might be able to get some (check to see if the Fed's are watching) plastic explosives if you want to get rid of the truck in a smoke show:smokin:.

Here's the text of a post I recently put up on another forum without any real help....

Last summer, it started cutting out really bad when I did anything to heat up the engine bay. That is to say, the truck wasn't running hot but if I idled on hot asphalt for example or did alot of stop and go on a hot day, the problem would surface. It should be noted that I do have headers on the truck so the engine bay heats up more than it would with the stock logs on there, I'm sure. However, the headers have been on the thing since 99 or 2000 without a prob. I chased all the obvious stuff; put new plug wires, plugs etc to no avail. The prob persisted for a couple of months until it finally lit up the check engine light. I took it to the shop to where I was told the oxygen sensor was bad. I went to the dealership and purchased an OEM brand new O2 sensor and installed it. Walla!!! The problem went away for the rest of the summer and through the winter.

The bad news: for the last several weeks it's been doing the same freakin' thing again. It acted EXACTLY the same this time as last even the part where it took several weeks to light up the light. Obviously, I suspect I got a bunk sensor. I'm gonna bite the bullet and go pick up an OBDII code reader today and pull the code. I would almost bet money it's gonna say bad O2 sensor again. My question is, assuming it does indicate the sensor is bad, are there any other probs anyone knows about that could cause this reading falsely? I hate to keep throwin money buying 02 sensors if it's something else. Could there be anything else wrong causing the sensor to fail prematurely? My plugs looked great when I pulled them.

Also worthy of note: The truck is equpped with a Jacobs Pro-Street capacitive discharge system, K&N filtercharger (the old style), the a fore mentioned headers, and the stock muffler has been swapped for a 70 series flowmaster. That's it for mods.

UPDATE: I have since gone and picked up a code reader which now tells me there are no codes stored. This is impossible with the check engine light lit on an OBDII vehicle, right? I sure would like to verify the damn problem before I through too much money at it.

Do any of you dodge boys have any suggestions as to how to proceed or what I might be missing?
One thing to remember is that a generic code reader does just that, it reads codes stored in what is called generic obd2. If you had a vehicle specific scan tool or able to be vin specific you can read factory codes which is where your code is probably stored. Kind of weird but sometimes its the other way around, no factory codes but generic codes, or sometimes in both. I would recommend taking it back to a repair shop instead of throwing parts at it, if you guess wrong the cost may add up and beyond what a repair bill would be. On the other hand you may guess right and save yourself some bucks, its a crapshoot.