Loses power randomly and sometimes stalls

If you observe the staling is more likely to occur during periods of coasting, connect a fuel pressure gauge, then clip it under a wiper arm where you can watch it. If the pressure starts to drop excessively just before the stalling occurs, let up on the accelerator pedal for an instant, then press it again. If the fuel pressure pops back up during that instant, suspect the pickup screen in the gas tank is plugged or collapsing.

As a possible test, you can disconnect the vacuum hose from the fuel pressure regulator, and plug it. That will cause the fuel / air mixture to be too rich, but the stalling will not occur. If that turns out to be the solution, I'll explain what is happening.

You really need the fuel pressure gauge to know what is going on. It is more common to have sensor-related problems, but your description of the symptoms sounds a lot more like the plugged pickup screen. You should be able to find a fuel pressure gauge with various adapters an the auto parts stores that rent or borrow tools. I just talked with the people at O'Reiley's a couple of days ago. They charge the cost of the tool, then give a full refund when you return it. If you decide you'd like to keep it, they ask you to bring that one back, then they give you a brand new one.

You have the luxury of learning from me! This happened twice to my cars with carburetors, and twice to my rusty trusty 1988 Grand Caravan. The part cost $3.00 for the two older cars. It just slid onto the pickup tube in the gas tank. The screen for my Grand Caravan costs $12.00 and snaps onto the housing the fuel pump sits in inside the tank. You will need to lower the gas tank which is best done after you run the gas out or siphon it out. I do not work on Fords but if you plan on doing more repairs yourself, invest in a paper copy of the manufacturer's service manual, not a Chilton's or Haynes manual. You can find these on eBay all the time. I bought a lot of Ford manuals for my classroom from a seller that does or used to go by the name of "Lorieandjeff", and later by "Blackhatauctions". They attend lots of dealership auctions all over the country and resell the books and special tools. They have a real lot of Ford stuff.

The manual will describe how to remove the fuel pump from the tank. I use the Rock Auto web site every day for reference. You can look up the part for your car to see what it looks like. It is real inexpensive but you have to add shipping. They call it a "strainer". I call it a screen. You are likely to find this in stock at your local auto parts stores too. The part for my Grand Caravan was in stock both times. The screen for my older cars were in stock both times when I worked at a very nice family-owned Chrysler dealership in the 1990's.

Before you dive into this, I would want to be sure it is the best suspect, and that is where watching the fuel pressure gauge is important. It would be the pits to go through all this work on my recommendation, then find out it did not solve the problem. If fuel pressure remains solid, (it will fluctuate based in varying intake manifold vacuum), another good thing to look at on every brand of car except Chrysler products is the fresh air tube between the mass air flow sensor and the throttle body. There cannot be any cracks, loose hose clamps, or other leaks in that tube. If any air sneaks in that does not go through the mass air flow sensor, the engine computer will not know about it, and it will not include enough fuel in the fuel metering calculations. Chrysler is the only manufacturer that never needed a mass air flow sensor to make their engines run right, so vacuum leaks do not affect engine performance that much.

To really shift gears for a minute, follow the smaller battery positive wire to the under-hood fuse box and be sure that connection is clean and tight. Follow the smaller negative battery wire to the body and be sure that connection is tight and not rusty. Those are common causes of intermittent electrical problems, including all the way up to a stalling engine, on any brand of car.

Beyond this, if nothing pans out up to this point, you will need a scanner to view live data during a test-drive. You can watch sensor readings and see how the computer responds. Most better scanners have a "record" feature that lets you record a few seconds of sensor data. You press the button when the problem occurs, then you can play it back slowly, later, to see what changed. Because the data goes through the scanner's memory, the recording actually starts a couple of seconds before you pressed the button.

I have a Chrysler DRB3 for all of my cars. A lot of independent shops bought them because with an extra plug-in card, it will do emissions-related stuff on any brand of car sold in the U.S. Starting with 1996 models. They are becoming obsolete now so you may find these at some local shops. They may be thrilled to sell theirs so they can buy something newer, but I do not recommend this for you. Everything it will do on your car is less than five percent of what it can do on Chrysler products. Ford does not have a dealer-level scanner that is practical for homeowners and do-it-yourselfers. For that, my friend has a Snapon Solus Edge that will work on most car brands. I will not buy Snapon equipment because of the customer-unfriendly business practice of grossly overcharging for annual updates, but that can work to your advantage. This model costs around $4,000.00 new, which sounds like a lot, but it is only slightly more than I paid for my DRB3's. Where they stick you is the annual updates cost $1,000.00, and you cannot skip any years. For that reason, these lose their value very quickly, and you can pick one up on eBay for around $800.00. For example, if you find one that has been updated to 2012, that is way more than good enough for your 1998 model. If a shop owner bought it for his business, he would be required to buy the 2013 update, the 2014 update, the 2015 update, the 2016 update, and the 2017 update before he could buy the 2018 update so it would work on the latest cars. Why buy $6,000.00 worth of updates when he could buy a brand new scanner with the latest updates for $4,000.00? This is why they lose their value for shop owners but they can be a good deal for you and me.

There are other brands of scanners that will work on your car. Consider asking at any local repair shop when their tool truck guys show up. Most visit each shop the same time each week, for an hour. The mechanics are usually in a hurry so you might have to wait until they are done, then the driver will be happy to show you what he has in his "used" drawer. Very often he is going to sell a new scanner to a mechanic once he can find a buyer for the mechanic's old trade-in. Once you use a quality scanner a few times, you will be amazed at what you could not do before without it.

I hear you. For the record, the first car this happened to for me was a 1978 LeBaron wagon at around 190,000 miles. I could easily drive it about fifteen miles at highway speed before the screen collapsed and blocked fuel flow. Let it sit on the side of the road for five minutes, then it would run okay for another five miles. Five to ten miles is all most dealers test-drive cars, so this problem would never have shown up until someone bought the car.

When this happened to my 1988 Grand Caravan the first time, it was during the hottest day of summer, right after leaving a stop light two hundred miles from home. It just had a little hesitation, just enough to get my attention. Thirty miles later, when turning off the highway is when it stalled and would not restart right away. I figured out later the screen was plugged and was being sucked closed by the pump trying to pull fuel through it. Five minutes later, the screen stretched out, and the engine ran fine for another five miles. Did my business, then the person suggested a different route home. That road had a stop light about every five miles, and I learned that when I let up on the accelerator to coast into the lower speed limit, that is when the stalling occurred. Next, with all three interstate bypasses down to one lane for road construction, it took me four hours to get through Minneapolis. Once out of town and back on the highway, the engine ran perfectly fine until I turned off three hours later.

Funny thing was this stalling was a big problem the next day too when driving near my home, but after that the outside temperature was twenty degrees colder, and the stalling never showed up again until six months later.

The second time this happened was when I was dragging a tandem axle enclosed trailer home from an old car show swap meet. That trailer is bigger and heavier than the van. I had the fuel pressure gauge clipped to the radio antenna for over a year, and noticed when straining to pull the trailer, the fuel pressure would drop real slowly from the normal 50 psi to less than 20 psi. Symptoms of minor surging and sputtering did not show up until it got close to 15 psi, then, if I lifted the accelerator pedal for just a fraction of a second, then pressed it again, the pressure would pop back up instantly, the start to drop again over about a twenty second period. By watching the gauge, I nursed it fifty five miles like that while keeping up with traffic. There is no way I would have been able to drive it or figure out the problem without the fuel pressure gauge.

This is where you cannot be a carpenter if you do not own a hammer. You cannot be an accountant if you do not have a pencil, and you cannot diagnose car problems without the equipment that is required. You can probably borrow a fuel pressure gauge from an auto parts store that rents or borrows tools, but if you plan on doing as many of your own car repairs as possible, spend your dollars on a used scanner instead of on a mechanic. $800.00 to $1,000.00 on a scanner can save you the cost of three trips to the shop, (one repair bill if it is a GM product).

P1132 - O2 Sensor Heater Control Circuit (Bank 1 Sensor 1)

To clarify, there's over 2,000 potential diagnostic fault codes an Engine Computer can set. Only about half of them refer to things that could adversely affect emissions. Those are the codes that turn on the Check Engine light.

I came up with a different definition for that code from a generic list. When there's a disagreement, your best bet is to do a Google search with your exact car model and year in the search terms, along with the P-code number.

One thing to watch out for that confuses too many people is there are dozens of fault codes related to oxygen sensors, and they mean very different things. Almost all of those problems are detected through a properly-working sensor. A real common code on Fords, for example, is P171, "Running too lean". The oxygen sensor just develops voltage signals based on the amount of unburned oxygen in the exhaust gas, then the computer figures out the exhaust is too lean. That problem can only be detected if the sensor is working properly, but people will replace it, thinking that is the solution.

The Engine Computer calculates fuel needs based on operating conditions and all the sensor readings, EXCEPT the oxygen sensor readings when the engine is cold. That is called "open loop". Oxygen sensors don't start to generate a signal voltage until they reach 600 degrees. It is assumed they reach that temperature about the same time coolant temperature reaches a predetermined temperature. When that occurs, the readings from the front oxygen sensors are added to the calculations from all the other sensors. That is called, "closed loop". Readings from the front oxygen sensors just result in fine tuning of the fuel / air mixture. It is very rare to have a noticeable running problem caused by an oxygen sensor.

The Engine Computer is constantly switching the fuel / air mixture between "rich" and "lean" about two times per second when in closed loop. The purpose is when it's lean, unburned oxygen is stored in the catalyst in the catalytic converter, then when it's rich, that oxygen mixes with the extra fuel and is burned. You never feel that slight change in mixture, so it's easy to see you won't feel a constant lean or rich mixture either unless it's really bad. If you had a leaking injector, you would see fuel pressure drop to 0 psi within a few seconds of stopping the engine. That pressure should hold for days if not weeks.

As far as "over-compensating", the Engine Computer only knows the exhaust gas is too rich or too lean too long. It doesn't know why. A common cause of a "lean" code is a spark-related misfire. That sends unburned gas and air into the exhaust system where it's the unburned oxygen that gets detected as the lean condition, but it's the unburned gas you smell at the tail pipe as the "rich" condition. The computers on most '96 and newer cars can detect which cylinder is misfiring by when the rotational speed of the crankshaft slows down slightly, but even when a misfire is not detected, in response to the excessive oxygen that was detected in the exhaust gas, the computer tries to fix that by adding more gas, but it does that equally to all the cylinders by pulsing the injectors open for a longer period of time. That is usually done to only half of a V-6 or V-8 engine. For a V-6 engine, you'll end up with two properly-firing cylinders getting too much fuel, and the misfiring cylinder still misfiring, and still sending excessive unburned oxygen into the exhaust system where it will continue to be detected as a lean condition. No matter how much fuel is added, it's the unburned oxygen that is always going to be detected. You can see this on a scanner by observing the short-term fuel trim numbers, (STFT). High positive numbers means the computer is requesting more fuel than the average that was programmed in at the factory.

I'd still do the Google search and look at the wealth of information, but I suspect the cause of this code is in addition to, not related to, or is just a secondary result of the underlying problem. The cause of P1132 should not have a major impact on engine performance by itself.