Need help - gas mileage for long road trip pulling a trailer 2k miles. Should I replace an outrageously priced O2 sensor or just bite the bullet and drive slow? Both?
Posted by Impressive_Limit_757@reddit | askcarguys | View on Reddit | 22 comments
I am about to load up my 2004 Toyota Highlander and move from North Dakota to Texas. I will be towing a motorcycle trailer (with motorcycle, obviously). On the drive up 2 years ago I got terrible gas mileage. I *may* have an upstream oxygen sensor out. The 2 in the front are upwards of $200 a piece. I don't know what would be cheaper - shitty gas mileage or outrageous O2 sensors.
What gear should I drive in towing the trailer? How can I maximize my gas mileage? Please, any help would be much appreciated, I am dreading filling my tank ever 160 miles. Money is tight and I am worried.
FreidasBoss@reddit
Why would you ignore a known problem? Just replace them and move along. You’re not doing your car any favors with two blown O2 sensors.
dascresta@reddit
Wait till the cats go out
The_Cat_Of_Ages@reddit
they live in north dakota, chances are that shits been deleted for a decade lmao.
worstatit@reddit
Or the cats gone already and the heat ate the sensors.
YeahIGotNuthin@reddit
Omg this.
The $200 oxygen sensor can wreck a catalytic converter. Also, towing will put a lot of load on everything and a lot of heat into the exhaust, which can lead to a very fun car fire
Impressive_Limit_757@reddit (OP)
Haven't driven the car in a year and it is 100 miles away.
Turbulent-Matter501@reddit
... has anyone else driven it in a year?
OBDSale@reddit
If the upstream O2 sensors are actually lazy/failing, they absolutely CAN hurt fuel mileage pretty badly, especially while towing. The ECU depends heavily on those sensors for fuel mixture adjustments.
That said, before dropping $400+ on sensors, I’d honestly scan the live data first and make sure they’re actually the problem. A lot of people replace O2 sensors when the real issue ends up being:
Check:
If the upstream sensors are switching super slow or stuck rich/lean, then yeah they may be worth replacing before a 2,000 mile tow trip.
For towing:
Honestly though, towing a trailer with a 20-year-old Highlander is probably going to drink fuel no matter what.
Visit OBDSale.com— they’ve got some beginner-friendly guides on common Toyota codes, fuel trims, and O2 sensor diagnostics that might help you verify whether the sensors are actually the issue before spending the money.
Impressive_Limit_757@reddit (OP)
I haven't driven the vehicle in a year and it is 100 miles away - I'll be picking it up to rent the trailer and be on my way that same day. F.... M.... L.
I can easily go to an autoparts store and have it scanned. I remember the downstream ones were bad and I had the CAT efficiency code but I can't recall what else came up.
Thank you for the response.
Euphoric_Local3265@reddit
Parts stores will try to sell you some bs after they scan it
20Factorial@reddit
You don’t need to buy the sensors from the dealer. Hop onto rockauto.com and order one for $70/ea (Ultra-Power) or Denso for $108.
If it has only sat for a year, do an oil change before you leave.
MostlyBrine@reddit
Depending what part of Texas you are going, you might need ro replace the O2 sensor anyway to pass emissions. And if you have poor fuel efficiency, the extra fuel burns in your catalytic converter, or worse is plugging it with soot, which means that you will soon need to replace it. Not spending $200 now, might force you to spend $2,000 in couple of weeks.
Boosted_Vet@reddit
if you replace later itll cost you more, the cost of the repair+ the extra gas. if you just replace the sensor now you only have one of those expenses.. Definitely scan first to make sure that's the problem, but I would bite the bullet and replace it first.
AgitatedHat5620@reddit
Replace the damn sensors before you cause a more expensive problem.
Mindless_Silver2754@reddit
Lol
Impressive_Limit_757@reddit (OP)
fml.
Hypersuccc@reddit
What engine and transmission combo is in it?
Impressive_Limit_757@reddit (OP)
I don't remember, haven't seen it in a year. It's the v6. :/
qkdsm7@reddit
*MAY* --- what's the live obd2 data show for short term fuel trim, long term fuel trim, and actual o2 sensor responses?
Spend the whole $20 to get a obd2 bluetooth dongle if you don't have one / don't know the answer.
Note: It may not use closed loop fueling during as much load as having a trailer on.... You'll also learn this when you get the data I've mentioned, and watching it while towing.... ;)
Impressive_Limit_757@reddit (OP)
I haven't driven the vehicle in a year and it is 100 miles away - I'll be picking it up to rent the trailer and be on my way that same day. F.... M.... L.
I can easily go to an autoparts store and have it scanned. I remember the downstream ones were bad and I had the CAT efficiency code but I can't recall what else came up.
This is going to be a long trip. On the up site - I'LL FINALLY BE PAROLED OUT OF THIS SHIT HOLE STATE.
MountainMark@reddit
I hauled my motorcycle on a trailer behind my Jeep. The gas mileage just sucked and it wasn't a weight issue. I had about 2000 lbs total & I'm rated for 3500. It's just that a motorcycle on a trailer (and I had a folding, expanded steel ramp made of expanded steel) just had awful wind flow.
quietguy47@reddit
I’d be more worried about other more expensive issues popping up by not getting that fixed now.