Was driving around town and got a pending P0130 a few times, then an actual trouble code P0130 and P0171. Ultragauge shows funky readings on B1S1 (Bank one? Sensor one?) It goes up to 1.1 and down to .000

Reading up, looks like I need a new O2 sensor on driverside front. Is the Bosch 15175 an OK sensor to use? (In stock locally.) I read that DiscoMike recommended to replace the O2 sensors in pairs. Should I replace both fronts? Or both on a side?

I couldn't find a post with only TWO trouble codes. Guess I'm lucky. I wanted your thoughts if the O2 sensor would fix it. When running, it smells really rich (gas smell), would that be the P0171?

Thanks!

 

HAPPY THANKSGIVING to all!

 

Yep, replace both fronts at the same time and when doing rears also do those at the same time. A bad O2 will often cause you to run rich.

Happy Thanksgiving!

 

Replacing the O2s in pairs is the conventional wisdom.

I tried to do so a few years ago and one of the two Bosch 15175s was bad out of the box so I reinstalled the old, good one to get rid of the SES light until I got around to replacing the new, bad one at Advance. I ended up driving it like that for at least 2-3 years with no problems, and with readings on the Ultragauge that showed the old O2 working just fine.

So although replacing in pairs is the conventional wisdom I have never understood the logic and my personal experience suggests it's not necessary.

And FWIW the rear O2s on my truck are still original, 16+ years and 153,000 miles later.

 

Put the new O2 sensors in and cleared the codes. Now I have more codes.....is this the rover life?

The new O2 sensors don't seem balanced? For example: Left side is often .200 and the right is .750. The back two are pretty static at .445. (The new sensors refresh much more often than the back two.) Is this normal?

The new pending trouble codes after O2 install are P0300 and P0307. Is plug 7 the driverside rear? Maybe the wire got bumped? The wires are blue and say lifetime, but I can't see a brand. PO installed them.

Ohhh and I found my throttle body heater leaks and drips right on the B1S1 02 plug connector and the left side valve cover leaks. Got a 12point socket and TBH kit on order.

 

The wisdom behind replacing in pairs is to maintain engine balance while running. O2 sensors have a part with fueling requirements , so if you have one bank adjusting faster than the other, then itehave a balance issue and wouldn't run as smooth as possible.

 

Interesting. Are there diagnostic readings that would show whether or not the concern you cite is having an impact real time? Speed of adjustment?

 

OK well p0171 is NOT rich... it means the system is running too lean. It's not going to have anything to do with your O2 sensors either if you're getting that code, I'd check for vacuum leaks before shelling out the cash for the sensors.

Fuel injector seals/o-rings could be the culprit too

 

New o2 sensors are already in. I'm really worried about the new PENDING trouble codes. PO300 and P0307. Reading online, seems the misfire on 7 is a bad thing.

What are my best troubleshooting steps here? Do I need to shell out $150 for wires and plugs?

 

First, you said the new codes are pending. Pending means just that --- the fault has not been detected "enough" to trigger an actual code/SES light.

If a P0300 and P0307 are triggered for real there is still not yet any reason to leap to installing all new plugs and wires. At least not yet. And if you do so I don't see why they'd cost $150.

What do you know about the plugs and wires in the truck? What brands are they, and for the plugs which part number? Pull the #7 plug and check its condition. Pull another plug for comparison. What do you see? Try taking a careful look at the engine while it's running in the dark. Do you see any arcing from any of the plug wires to the engine, especially from the #7 wire?

Looking at your posts I see you bought the truck a little under two months ago from a Craigslist seller. Did you get maintenance records? Can you contact the seller and ask about the plugs and wires?

When I got back into wrenching six years ago this month after being away 25+ years the first thing I had to do was diagnose and correct a misfire problem. When I last really worked on cars it was breaker points and carburetors and there were no ECUs and BCUs. There were no anti-lock brakes and no MPFI. But I digress.

In my case the only problem turned out to be that the "professional, Euro-specialist" shop that serviced the truck for the 6+ years it was my wife's daily driver installed plain old copper Champions just a couple of years earlier instead of the double-platinum plugs specified for a wasted spark system like my '99 DII. I changed the plugs to the specified Champion RC11 PYP B4 plugs and they've performed great for the last six years and 45,000 miles.

Luckily for me the mechanic had installed STI wires at the same time the plugs were installed and they are still going strong, although I think I damaged one of them when I replaced the plugs. I contacted STI and they promptly sent out a new one at no charge. STI is one of a handful of brands recommended by forum users, and I add my name to that list based on not only how well they've worked for now 10+ years but even more based on the great customer service and support. I also wasted a lot of time lying flat on my stomach on top of the engine (on a camping sleeping pad, without removing the upper intake) pulling the coils to try to "test' them. That was a waste of time. As P.T. Schram advised me at the time, DII coils fail rarely. Live and learn.

The point of all of this is diagnose, diagnose, diagnose. Don't just throw parts and money at your problems.