SES: O2 or headers

[borispeed]

A year ago headers were installed and no SES for more than a week (about 90,000 miles). After that: SES :( The codes said right and left bank was the reason. After a year (with more than 114,000 miles) I've been thinking to replace O2 sensors due to the decrease of 4 or 5 m/g., but at the same time I don't just want to spend money on that if I'm not sure that's the reason. I planning to tune the PCM soon. So my questions are:

Did the SES came on due to a normal thing when you installed headers (I've read about it)?

or

Is there's a possibility that when you reuse the same O2's (with 90,000 miles old), they are very sensitive to be removed and reinstalled, in such way that you need to replace them.

or

Is it better to wait until I tune the PCM, then a probability that the tuning will erase the SES from my dashboard? (assuming that O2 would be OK and then the 4m/g would be saved by the tunning) :naughty::rolleyes:

or

Is there another idea

[bigbrian442]

Re: SES: O2 or headers

O2 sensors are a 40,000 mile throw a way item. Most don't last that long before they start giving less the perfect performance/ fuel economy. If yours have 114000 on them replace them. You need to be specific about what codes your car set with the headers. When you tune the PCM you should have new O2 sensors installed and a wide band O2 to tune your AFR.

[borispeed]

Re: SES: O2 or headers

O2 sensors are a 40,000 mile throw a way item. Most don't last that long before they start giving less the perfect performance/ fuel economy. If yours have 114000 on them replace them. You need to be specific about what codes your car set with the headers. When you tune the PCM you should have new O2 sensors installed and a wide band O2 to tune your AFR.

I need to come back to autozone to get those codes
Sorry about my ignorance, What's wide band O2? What's AFR?

[bigbrian442]

Re: SES: O2 or headers

I need to come back to autozone to get those codes
Sorry about my ignorance, What's wide band O2? What's AFR?

AFR = Air Fuel Ratio


http://en.wikipedia.org/wiki/Air_fuel_ratio



The narrow band O2 sensors your PCM uses to determine the AFR are only accurate at an AFR of 14.7-1 ( stoichiometric AFR). When you tune wide open throttle (WOT), If not using some type of forced induction ( blower, turbo....) Your WOT AFR should be between 12.5-1 and 13.3-1. The wide band O2 accurately reads this.

[borispeed]

Re: SES: O2 or headers

AFR = Air Fuel Ratio
http://en.wikipedia.org/wiki/Air_fuel_ratio
The narrow band O2 sensors your PCM uses to determine the AFR are only accurate at an AFR of 14.7-1 ( stoichiometric AFR). When you tune wide open throttle (WOT), If not using some type of forced induction ( blower, turbo....) Your WOT AFR should be between 12.5-1 and 13.3-1. The wide band O2 accurately reads this.

Very good explanation and very interesting information from wikipedia. It looks pretty complicated to install a wide band O2 according with one of the links from wikipedia. There're tuners like hypertech that you just plug them below the steering wheel and you choose the air-fuel setting. But I've heard there're programmers that give much better results. Is there something easier and better than hypertech?

[bigbrian442]

Re: SES: O2 or headers

HPtuners is the program to get. Comparing Hypertech to HPtuners is like comparing a little red wagon to a F1 car. The wide band screws into an O2 bung in the exhaust and everything plugs in from there.
you only use the wide band while tuning, it never gets hooked to the PCM.

[borispeed]

Re: SES: O2 or headers

HPtuners is the program to get. Comparing Hypertech to HPtuners is like comparing a little red wagon to a F1 car. The wide band screws into an O2 bung in the exhaust and everything plugs in from there.
you only use the wide band while tuning, it never gets hooked to the PCM.

How much does the wide band cost? Is the O2 bung where the sensor goes?

[bigbrian442]

Re: SES: O2 or headers

Wide bands are about $200 and up depending on what you want. You can remove one of your stock O2 sensors and put the wide band in that bung or have a bung added.

[borispeed]

Re: SES: O2 or headers

Wide bands are about $200 and up depending on what you want. You can remove one of your stock O2 sensors and put the wide band in that bung or have a bung added.

I heard hptuners is about 450-500 bucks + 200 or more for the band = $700 or $750 :eek: Well, if is not too complicated to do the tuner and band, then it would be a good investment :rolleyes:

[borispeed]

Re: SES: O2 or headers

I have an update in this issue. I went to autozone and I got 2 codes: P0420 (Catalyst efficiency low bank 1) and P0135 (HO2S 11 - Heated Oxigen Sensor Bank 1 sensor 1).

As I said, a year ago headers were installed, what I forgot to say at the beggining of this thread is that I have a leak in the connection of EGR tube and headers, same story that some of you are dealing with. Also when I did headers, I did high flow catalyc (Dynacat) too that is off-road but complies with OBDII (according with the manufacturer). So far the car is running great, with a decrease in fuel of about 4 or 5 mpg.

So about the codes, the autozone computer gives the following probable causes:

P0420
1 - Catalytic Converter defective (failure possibly due to #2, 3, or 4)
2 - Engine misfire or running condition.
3 - Large vacuum leak
4 - Engine oil leakage into exhaust-valve guide seals piston rings.

P0135
1 - Oxigen sensor defective.
2 - Poor connection at oxigen sensor
3 - Check circuit fuse

I need your help guys, What do you think?

[FadeToBlak121]

Re: SES: O2 or headers

replace your cat and the bad oxygen sensor.

[borispeed]

Re: SES: O2 or headers

replace your cat and the bad oxygen sensor.

But the OEM cat was replace for this one a year ago!

[FadeToBlak121]

Re: SES: O2 or headers

could be you were sold a bad cat i guess? you should try to figure out why its getting clogged though. do you have a misfire? check for vacuum leaks check for leaking oil. either way, im sure youll still have to replace the cat because it is clogged now by something.

[borispeed]

Re: SES: O2 or headers

Well, about the misfire I don't know. Sometimes the tailpipe gives an irregular sound or puff when the car is idle. I started to give serious maintenance when the car was 60,000 miles. Now have around 114,000 miles. The oil is replaced every 3,000 miles with Lucas stabilizer. I did spark plugs and wires when it was 75,000 miles and 3 months ago. Fuel filter was replaced when it was 75,000 miles and a week ago again. I use Chevron gasoline only. A week ago I add concentrated fuel cleaner to the tank.

[bigbrian442]

Re: SES: O2 or headers

1-Fix you exhaust (EGR) leak. That will give false information to the O2 sensors.

2- Check the fuse for the O2 sensor, if blown replace it, if not replace the O2 sensor. Bank 1 is the drivers side.

3- Running rich will kill a CAT, the after cat O2 could be bad and is cheaper than replacing the CAT again. Can you pull the CAT off and inspect it?

My mileage went up over 3 MPG with headers, high flow CAT and CAT back.