dnewton3
Staff member
My 1997 Taurus with almost 95k miles on it just started doing some bizzare things out of the clear blue sky. I'll take all reasonable input as to what might be the cause(s), and cure(s).
Problem: car started giving me the check engine light a few days ago. Checked with OBDII reader; got all four O2 sensor codes. Don't recall the codes (P0135, P01 ... etc), but they were for Bank 1 Sensor 1, Bank 1 Sensor 2, Bank 2 Sensor 1, Bank 2 Sensor 2. All four code pop up at the same time. I can clear them, and they will reappear almost immediately upon the next start cycle.
Conditions: Normal driving, moderate OA temperatures. All other engine and vehicle systems seem to be normal. No "running hot or cold"; temp gage fine. Drive train operates normally (i.e. - accelerates fine, steady throttle fine, no hesitation or stumble, etc). Transmission shifting fine. Can clear codes, and will return within a minute or so after start-up.
Plausible causes: Either fuel or electrical problems. I don't know that a mechanical issue could/would cause this.
Doubtful causes: While possible, I rather doubt all four O2 sensors took a dump and went belly up all at the same time. Now, one thing to consider is that rather than the individual sensors going bad, is the whole O2 circut or ECM going bad? It's certainly possible, but I'm not sure how probable. I don't see any obvious contributors like loose or chaffed wires going to ground, but it's hard to see all the wires in today's vehicles, so I may have missed something?
Suspicion: Bad fuel. The reason I say this is that the problem occured on the very first start cycle after I got a full tank of gas at my regular (high sales volume) fuel station. Could I have gotten a load of "bad" fuel? Perhaps over/under "oxygenated" and leading ECM to display error codes? If I remember correctly, the Taurus engines of that era use narrow-band O2 sensors, so being out of range may not be a far fetched event? All performance characteristics of the vehicle otherwise indicates the fuel is fine (again, good driving, no pinging, etc). My intent is to continue to drive out this tank to a very low level, so that when I get a new load of fuel, it will represent the bulk of the fuel capacity. In other words, I don't want to "blend" in some new fuel from another source, and then have the CEL come on intermittently. If I can burn this load out, and then refill and have the problem vanish, I'll have confirmed the suspicision. But to top off evey 5 gallons will only lead to a variable that is difficult to track by percentage of total fuel load.
The reason I'm posting is that I'm looking for anyone with similar/same experiences, and specifically wanting to know of any solution that cured the problem. I'm not on an unlimited budget, so replacing parts on a "hunch" really isn't my style.
Problem: car started giving me the check engine light a few days ago. Checked with OBDII reader; got all four O2 sensor codes. Don't recall the codes (P0135, P01 ... etc), but they were for Bank 1 Sensor 1, Bank 1 Sensor 2, Bank 2 Sensor 1, Bank 2 Sensor 2. All four code pop up at the same time. I can clear them, and they will reappear almost immediately upon the next start cycle.
Conditions: Normal driving, moderate OA temperatures. All other engine and vehicle systems seem to be normal. No "running hot or cold"; temp gage fine. Drive train operates normally (i.e. - accelerates fine, steady throttle fine, no hesitation or stumble, etc). Transmission shifting fine. Can clear codes, and will return within a minute or so after start-up.
Plausible causes: Either fuel or electrical problems. I don't know that a mechanical issue could/would cause this.
Doubtful causes: While possible, I rather doubt all four O2 sensors took a dump and went belly up all at the same time. Now, one thing to consider is that rather than the individual sensors going bad, is the whole O2 circut or ECM going bad? It's certainly possible, but I'm not sure how probable. I don't see any obvious contributors like loose or chaffed wires going to ground, but it's hard to see all the wires in today's vehicles, so I may have missed something?
Suspicion: Bad fuel. The reason I say this is that the problem occured on the very first start cycle after I got a full tank of gas at my regular (high sales volume) fuel station. Could I have gotten a load of "bad" fuel? Perhaps over/under "oxygenated" and leading ECM to display error codes? If I remember correctly, the Taurus engines of that era use narrow-band O2 sensors, so being out of range may not be a far fetched event? All performance characteristics of the vehicle otherwise indicates the fuel is fine (again, good driving, no pinging, etc). My intent is to continue to drive out this tank to a very low level, so that when I get a new load of fuel, it will represent the bulk of the fuel capacity. In other words, I don't want to "blend" in some new fuel from another source, and then have the CEL come on intermittently. If I can burn this load out, and then refill and have the problem vanish, I'll have confirmed the suspicision. But to top off evey 5 gallons will only lead to a variable that is difficult to track by percentage of total fuel load.
The reason I'm posting is that I'm looking for anyone with similar/same experiences, and specifically wanting to know of any solution that cured the problem. I'm not on an unlimited budget, so replacing parts on a "hunch" really isn't my style.
