O2 Sensor Cleaning For Fuel Economy?
03-28-2018, 12:23 AM
#46
CF Veteran
totally peaceful... I just figured since exhaust got brought up like that, I wasn't really thread jacking to just poke in and ask that. I dont know. does the entire intake have to come off on a 99 to replace it? Or is it recommended because it's a royal PITA to NOT take it off to get at it?
I just have a little getting by on the very front cylinder exhaust port.
I just have a little getting by on the very front cylinder exhaust port.
03-28-2018, 12:30 AM
#47
CF Veteran
Yes intake has to come off. No going around that. The intake and exhaust gasket are all one piece so everything has to be clear. You can leave the header bolted up to the collector but it makes it a bit more of a pain.
03-28-2018, 03:16 AM
#48
CF Veteran
Where are you taking the reading from? Collector or primary tubing? Primaries you get a pulse thats goes into vacuum(using electronic sensors. Looks like the pulse of an o2 sensor). Collector, ehh not so much. Greatly depends on exhaust systems though. Equal length header makes a huge difference in the readings.
03-28-2018, 06:47 AM
#49
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I have tested. Thats why i am asking the location you tested at. There is a big difference from testing each primary tube to testing at the collector (and not all collectors are created equal). And on top of that there is an even bigger difference when testing near the muffler.
03-28-2018, 10:32 AM
#50
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03-28-2018, 11:38 AM
#51
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03-28-2018, 04:43 PM
#52
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Just to follow up, refurbished 4 hole injectors seem to have solved my startup problems. I’d be surprised if my mpg doesn’t improve dramatically. If it remains at the 13mpg it’s been around town, I’ll look into replacing O2 sensors.
Last edited by ElMartillo; 03-29-2018 at 10:42 AM.
03-30-2018, 08:04 PM
#53
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Huge improvent in mpg with the new injectors. I had 56 miles logged on a 1/4 tank used when I did the swap. That is city miles. I then drove 60 miles on the freeway, then about 45 in the mountains climbing to about 7K feet. Drove down this am. In the subsequent 1/2 tank since the injector swap I did about 190 miles. Nearly double the mpg I was getting before. When I fill up in the am I’ll do the actual math. Still doesn’t feel as peppy as my ‘96 though, but that’s ok. I know this is no hot rod.
If my mileage is really as improved as it seems, I’ll leave my O2 sensors as is for now.
After doing the math at fill up I’m at 17.3 mpg for the last tank full. That is with the first 1/4 tank with the old injectors. That’s more like it
UPDATE: I think my improved mpg was simply because of all the freeway driving I did. Still poor around town. I just installed a new O2 sensor (see below) and expect this to make an improvement in fuel economy.
If my mileage is really as improved as it seems, I’ll leave my O2 sensors as is for now.
After doing the math at fill up I’m at 17.3 mpg for the last tank full. That is with the first 1/4 tank with the old injectors. That’s more like it
UPDATE: I think my improved mpg was simply because of all the freeway driving I did. Still poor around town. I just installed a new O2 sensor (see below) and expect this to make an improvement in fuel economy.
Last edited by ElMartillo; 05-02-2018 at 05:05 PM.
04-25-2018, 02:13 PM
#54
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Thread Starter
Still getting poor “around town” fuel economy, although I am very conservative with the accelorator at all speeds. In searching for an O2 sensor, I’m only coming up with one part number. I ordered the correct NTK sensor, but it’s described as an “upstream” sensor, located between the header and the cat. Looking at my vehicle, I see the one sensor. No others. Is there another O2 sensor somewhere that I should also replace while I’m at it?
Thanks.
(‘91 XJ Sport 4wd 4.0)
Thanks.
(‘91 XJ Sport 4wd 4.0)
04-25-2018, 02:17 PM
#55
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You only have one and it is an upstream sensor. Downstream oxygen sensors go after the cat to monitor its effectiveness.
04-26-2018, 10:03 AM
#56
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05-02-2018, 05:01 PM
#57
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Installed the new NTK sensor part #23023 and performed the ECU reset described in another thread.
So far just drove it back to the auto parts store to return the loaner O2 sensor socket. Startup seemed better, and it seems more responsive to accelerator. Since I purchased it a few weeks ago, this XJ has underwhelmed me compared to the peppiness of my other two XJs. I hope this is the remedy it seems to be. I’m also hoping the mpg will go up from the 13 mpg it’s been getting me around town. I’ll monitor and report my findings.
So far just drove it back to the auto parts store to return the loaner O2 sensor socket. Startup seemed better, and it seems more responsive to accelerator. Since I purchased it a few weeks ago, this XJ has underwhelmed me compared to the peppiness of my other two XJs. I hope this is the remedy it seems to be. I’m also hoping the mpg will go up from the 13 mpg it’s been getting me around town. I’ll monitor and report my findings.
05-02-2018, 05:55 PM
#58
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Also I had Toyota 20R burn an exhaust valve when a manifold bolt right there had come out. Presumably it sucked O2 in through the bolt hole into the port where un-burnt fuel burnt and overheated the valve.
OP, 746"s are a slightly better match for your 89. >https://www.cherokeeforum.com/f2/199...r-swap-163105/
05-02-2018, 06:37 PM
#59
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OP, 746"s are a slightly better match for your 89. >https://www.cherokeeforum.com/f2/199...r-swap-163105/
