o2 sensor and headers
 

ok i got my headers on and i was wondering if i should put the o2 sensor in the collector or i was looking at the header it has a bung on the last pipe made for an o2 sensor..which one should i put it on

the sensor will read more accurate if you use the one closer to the engine,and you won't have to buy an o2 sensor with longer wires,like you may have to do if you put it on the collector.

my headers had a bung on each collector. i ended up putting the o2 on the drivers side. i did this because the sensor would have hit the tranny cooling lines. all i did was cut the wires, and solder in 2' pieces and shrink tubed them, wrap em in tape and good to go.

I have mine about an two inches from the collector flange and i didnt have to splice anything. Just unwrap the plastic covering and theres about more than enough to get you almost to the flange. On the o2 wiring.

iv been reading and people said it effects your vehicle if you move it and stuff...so would it be alright if i do use the bung on the header...the bung is on the last cylinder pipe

This is where mine is right now with longtubes. I don't know what I was thinking at the time, I should have put it in the header collector before the flange but in any case it seems to work fine. I did not have to add any wire to the sensor to reach this location either, just removed the tape from the harness and pulled out some extra, though that is an aftermarket sensor with a longer lead.

http://farm4.static.flickr.com/3138/...0a5676d2_z.jpg

Looks like Paul and I have the exact same header setup. I have been running my O2 sensor right at the collector (about 8 inches upstream of Paul's location) with LT headers for several years now.

I did replace the sensor when I swapped headers.... i believe a bosch part. But there was no need for any extension.

FWIW... my headers are FlowTech.

IIRC my o2 is right b4 the cat. so if i got headers and full exaust i should move the o2 to the headers? will this F up anything? im due for an inspection in march and replacing the cat and muffler anyways bc they are both rotted and leaking.

Just replace the Cat. with a reputable brand (e.g. Magnaflow, RPI etc.) with a visible P/N the inspector can reference. If your truck is OBD-I, just place the o2 bung in the collector (similar to Paul's picture above) and make sure you have a return line for your secondary air pump if you will be truly emissions compliant. You just want your o2 sensor approximately the same distance from the cylinder head as it was stock. That's it.

I used a Magnaflow 400 cell 3" in/out cat for my replacement. The P/N is visible on the underside of the piece. I also re-used (I just cut it off with a rotary wheel) the secondary air line and had that added to the Y-pipe I had built. Passed visual inspection in CA, NV and WA...along with the sniffer.

All in total, I paid just over $300 for my custom y-pipe, Magnaflow Cat (that thing was $100), O2 bung and air return installation, and 3" single side exit Flowmaster 40. Installed.

I drove the truck with open headers and no exhaust (after I installed the headers-only about a 2 mile drive) down to the exhaust shop for this work. Took the guy about 3 hours to finish up. Been on the truck since 2007 and about 60,000 miles. Not one burp or issue later.

sounds good. yes i was going to buy a magnaflow cat anyways. so i can route one of the two tubes into the ypipe instead of poping the extra $90 for a direct fit cat? also i had a 40 series on my bronco. 5.0 and i wasnt happy with it at all.. not loud enough? are you happy with it?

Yep. And your EGR will be happy and no CEL on the dash.

It's quite loud. However, with the limited flow on a stock Y pipe the exhaust flow (and sound) is pathetic. Once you replace the stock Y-pipe and cats (the true bottleneck on these SBF trucks) the motor really opens up. I'd take a vid-clip right now for you, but I'd wake my sleeping 9-month old, and my neighbors would not be happy. When my wife drives the truck, I can hear her coming from a long ways away...and she drives like a grandma.

When I get my E4OD tuning right, I will opt for a longer more efficient sound deadening muffler and sh1tcan the 40 series. It gets loud. Right now, the motor won't hit much of anything past 4000 rpms with the way this transmission shifts. On the dyno, the motor pulls well past 5,500 rpms. When my shift points for 1-2 are dialed in the higher rpm's, the flowmaster 40 will likely be replaced with something quieter.

well i have to keep in mind u have a built 302. i had a stock bronco except for summit shorties magnaflo cats and the 40. i wasnt happy with it at all...my truck now is a 5.8. its pretty much stock and will stay that way for now except for a new cat and muffler...now y did u spend that money and only go to a 306? y not a 347?

It was a very cheap build that way. I spent just over a grand in machine work and parts. The only real money I spent was on the head work. I don't think a 347 would run as well as this 306 using stock ford EFI/MAF junk, and stock Ford PCM. And I still haven't been sold or bit the bullet on a tuning solution for this motor and trans. combination.

The extra displacement would be nice in hindsight, but the truck scoots very well as is with the power upgrades and 4.10's. If I could only keep it in gear longer through 1st and 2nd gear without the lazy 2500 rpm shifts, I'd be happy as pie.

Truck gets a legitimate 16 mpg's as well. Even turning 33" tires and with 4.10 gears.

Well nice truck... don't see someone with a bmw that nice and also a 90's truck lol

....The stock PCM will work fine , just upgrade the MA meter and have a custom tuned chip burned for it , just need to find a good tuner , your motor will make more hp ang tq , and you can get it to shift at cruise or wot where ever you want it to....Lew