O2 sensors and such

[BluebyU]

I just got "belle" back from the dealer today. One of my O2 sensors is bad and it's not covered under warranty. I have an estimate from the dealer, but was wondering if anyone knew of a place that I could take it in either Lancaster or Chester county if I bought the parts off the net versus the dealer. I don't want to take it to LCM. Which actually leads me to my next question.....where can I get parts? I don't want to pay for my parts wait forever to get them. I know of 1stsubaruparts and subaruparts. Has anyone had good luck with either of them? I know that I saw a posting by someone recently for a dealer in Jersey somewhere.....but I can't remember the name or what post it was in.

Any ideas or suggestions?

P.S.....is it safe to drive her all the way to Indiana with a bad O2 sensor? It seems to drive ok aside from the fact that the light flickers every now and then......

[vkykam]

If you have jackstands, it'll take you 1/2 hour and $80-$100USD for the sensor. It's not that hard at all.

VK

the place were they worked on my car said the computer is giving off a bad o2 sensor code...but i have no lights on...anyways i want to get them on before the trip, were is the best place to buy them?

[vkykam]

You can either get them from subaruparts.com or 1stsubaruparts.com, or you can pick up the Bosch ones from any parts store.

If you get it from the parts store, don't let them sell you the NGK ones, as the application is listed wrong in the catalog. NGK seems to think we have a one wire unheated one.

FWIW, I'm running Bosch ones in the car right now.

VK

[benebob]

Bobby

Another place to try is Liberty Subaru. I'm pretty sure they're out of NJ so it shouldn't take that long to get here (1stsubaru.com is on the west cost). If you didn't see my post it looks bleak for me to go to Lafayette. 712 bleak! Oh well my SVX is running real good right now (except I think they forgot to plug the radio antenna back in). My new Koni's are fabulous!!!!!! It feels almost like a Lotus!!!!!!!!!!!!!!!

Liberty is in Oradell.

http://www.newsubaru.com/LIBERTY/Partsx.html

Get an oil change, hand the 02 sensors to the mech with a $10 bill. With the car on a lift it takes 3 minutes per. Period. In fact, it wouldn't take that long if they weren't so hot!

Originally posted by LagunaBluebyU


I just got "belle" back from the dealer today. One of my O2 sensors is bad and it's not covered under warranty. I have an estimate from the dealer, but was wondering if anyone knew of a place that I could take it in either Lancaster or Chester county if I bought the parts off the net versus the dealer. I don't want to take it to LCM. Which actually leads me to my next question.....where can I get parts? I don't want to pay for my parts wait forever to get them. I know of 1stsubaruparts and subaruparts. Has anyone had good luck with either of them? I know that I saw a posting by someone recently for a dealer in Jersey somewhere.....but I can't remember the name or what post it was in.

Any ideas or suggestions?

P.S.....is it safe to drive her all the way to Indiana with a bad O2 sensor? It seems to drive ok aside from the fact that the light flickers every now and then......

LB, Bad oxygen sensors make the engine run rich and could mess
up the catalytic converters. I'm told nowadays that O2 sensors are a standard tune-up item, like spark plugs. After a bad experience with Subaruparts and a worse one with 1stsubaruparts I cast my net a little wider and found www.partsbin.com I just ordered 2
oxygen sensors (Bosch) for 74.03 each. AutoZone wanted $90 bucks each and their vendor is out of stock. Even got an email confirmation that I didn't even ask for unlike the other outfit's where I specifically requested an email confirmation and got squat.

[Beav]

I would seriously consider replacing both sensors at the same time. The fuel system works as two individual banks, each basically controlled by its own O2 sensor. As the sensor ages it becomes sluggish in its response to changes in the exhaust. What you end up with is one bank running at peak efficiency and one that isn't. It's not a requirement to replace in pairs, just a generally accepted practice.

First, you can drive any closed-circuit car with a nonperforming O2 sensor - generally without fear of damage because the ECU will keep the mixture within reasonable, if not efficient, limits. If the sensor is erroneously reporting "lean" you will burn excess fuel. If it is reporting "rich" you will lose power (knock sensor will retard ignition). I also suggest that after replacing the O2 sensor you disconnect the battery overnight to get the ECU back to the LEARN mode.

Second, on this car it makes no sense to replace both at the same time. Let the computer tell you which sensor has gone out of spec. I've never heard of "sluggish" response, and even if there were such a thing I wouldn't particularly care if my O2 sensors took an extra 100 milliseconds to report mixture changes.

Third, if you can't find the correct multiwire O2 sensor, buy the simplest/cheapest - though you'll have to determine which is the signal wire and which go to the heater, and you may have to adapt the connector or do a splice. If I recall correctly, the only difference is the time it takes to heat up to its best temperature range.

Fourth, (to reiterate), replacing an SVX O2 sensor takes no time and no skill - though it's much easier with a lift, and more comfortable on a cool engine. Be sure to apply anti-seize to the threads...

[Beav]

I suppose we can agree to disagree on this. I make my living by making recommendations that keep my customers happy. They stay happy when their cars run properly and they don't have to keep coming back in for niggling complaints. For those that do their own work and don't mind fiddling and piddling around, more power to them. I just sometimes make recommendations to help people reap the maximum benefit of the repair. If someone says they're going to do brakes on one wheel only, I'll jump in for obvious reasons. This is just my opinion, but it comes from a basis of knowledge and experience.

O2 sensors can grow to be sluggish, it happens quite often. They report in a voltage range of 0-1 volt. Lean and rich are determined by a 'threshold' of around .46v. The sensor can 'hang' around .4 to .5 (for the sake of discussion, the voltage threshold is what we're interested in here, not the actual voltages), crossing the threshold back and forth enough for the computer to think everything is o.k. but not actually accomplishing the job they were designed to do.

The cross-counts (the amount of times that the voltage passes the threshold) are how the computer determines if the sensor is good or bad (shorts to gound or power excepted.) So while a sluggish sensor can produce a cross-count it isn't representing the true state of combustion. The fuel can be too lean and cause a lean misfire and high CO or too rich and have high HC. Either way the car doesn't run well, plugs can foul easier, convertors can melt, the oil can be diluted and wear bearings and rings prematurely, the driver can experience a bobble in the idle, etc.

The computer doesn't need to be reset after replacing the sensor, it will react normally as the sensor reports. The long and short term fuel trim strategies will adjust quickly without forcing the system to return to its default settings. Resetting it would only create a prolonged relearn procedure for all parameters. When I cleaned my throttle body and re-adjusted the TPS the relearn took six drive cycles to complete and for the idle to return to normal. The point here is that the computer will adjust the fuel trims more quickly if it isn't reset.

No problems with using a sensor from another application, just make sure you solder the connections and insulate them well. Anything that will cause a voltage drop or a poor connection will affect the way the car runs.