I have pacesetter headers on my 22re and would like to know the best place to add an o2 sensor. I've read in an old Downey catalog that this is a big deal on their header design. Also, where is the connector underhood? Thanks.
85 EFI o2 sensor placement (1 Viewer)
- Thread starter thetoyotaman
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WarDamnEagle
SILVER Star
I'm assuming you mean "header" as it's a 22re. I installed an LC engineering header and stainless exhaust system. On that install, there is an 02 bung built into the pipe between the header and the CAT (see red circle on photo). You have to extend the wiring for the O2 sensor.
my header (JT Outfitters)has the O2 bung already in the #2 pipe and its OK but sometimes at low rpm the check engine light comes on from the pulsing signal it receives....in other words you want it after the 4 downpipes have mixed 2gether
- Thread starter
- #4
I'll have to weld a fitting on the pipe somewhere to add one. I'm concerned if it is too far downstream it would have too much of a delay for the computer.
I'm also not sure where the connector is under the hood. Can someone post a pic of it? Thanks.
I'm also not sure where the connector is under the hood. Can someone post a pic of it? Thanks.
Sorry, I don't have a pic for you but the O2 bung needs to be before the cat but after the header collector.
WarDamnEagle
SILVER Star
You can barely see my O2 sensor in this photo:
It's just below the end of the brake master cylinder. That's an LC Engineering header, about 2000-era. I now have a hole in the O2 bung, so occasionally my CEL light comes on. The wire comes out of the harness right next to the brake fluid warning switch.
It's just below the end of the brake master cylinder. That's an LC Engineering header, about 2000-era. I now have a hole in the O2 bung, so occasionally my CEL light comes on. The wire comes out of the harness right next to the brake fluid warning switch.
You can barely see my O2 sensor in this photo:
It's just below the end of the brake master cylinder. That's an LC Engineering header, about 2000-era. I now have a hole in the O2 bung, so occasionally my CEL light comes on. The wire comes out of the harness right next to the brake fluid warning switch.
oh damn!!!
thats the nicest looking engine bay i have ever seen!
:chreers:
A non-heated o2 sensor (such as the 1 wire found on a 1985 toyota) MUST be put as close to the engine as possible.
If mounted downstream, the exhaust will cool, and it will not function properly. I've failed smog before, when my o2 was 2' from the engine (base of the firewall), as it would not run as efficiently. After swapping in a new downey header, with a new exhaust, my mpg went from 12-14 to 16-20.
If mounted downstream, the exhaust will cool, and it will not function properly. I've failed smog before, when my o2 was 2' from the engine (base of the firewall), as it would not run as efficiently. After swapping in a new downey header, with a new exhaust, my mpg went from 12-14 to 16-20.
I have a Thorley header on my truck with the Ox sensor reading off one tube. I had a problem passing smog and it was surmised that the sensor was getting cold causing a rich condition at idle. I took the truck to a muffler shop and they installed an Ox sensor bung after the header, before the cat. I then installed a three wire Ox sensor for a 1994 Chevy Astro (Denso 2343005, Bosch 13077). It came with a Weather-pac connector and I made a harness to wire it up to the rest of the truck.
You would swear the guy was a mall crawler too look in his engine bay, but Ive seen him tearing it up on the trails with my own two eyes. Man I covet that rig.
Ken I dono how you do it.
That picture was taken 4 years ago, so to be honest it's not quite that pretty under the hood now. But, if I can get my garage setup I hope to be starting on a frame-off this Spring.
- Thread starter
- #13
I'm wondering if anyone sells the 2 bolt bung adapter for the Toyota O2 Sensor. If I did put one in one of the header pipes how close to the head should it be? Also, it seems the smaller pipes there wouldn't do well to be air flow blocked by the sensor in there.
Slee sells the fitting, but they are spendy. Best to cut one from a boneyard Toyota. I you get desperate I should have one I can send you. 
If you run a factory unheated (one-wire) sensor it needs to be as close to the head as possible. Best to install a heated sensor (3 or 4-wire) down stream that reads off all the cylinders.
If you run a factory unheated (one-wire) sensor it needs to be as close to the head as possible. Best to install a heated sensor (3 or 4-wire) down stream that reads off all the cylinders.
WarDamnEagle
SILVER Star
WOW. How does Slee get away with selling theirs for $28? The issue isn't the time from the header to the sensor, it's the temperature. The sensor needs to be real hot to work.
WarDamnEagle
SILVER Star
I bought the stainless header and stainless exhaust system (and a CAT) from LC Engineering. My O2 sensor is about a foot past the header (red circle in photo). The kit came with wiring to extend the O2 sensor connector wiring by 3 or 4 feet.
