MAF sensor

[ACE-tC]

Hey people i tried looking for this subject on the site but didn't find it and i'm not sure if this goes here but I have a question.

So i went to have my codes read and basically they told me to get a new MAF sensor. I was also told to just get the same model and all that stuff but my question is and from what i've heard should i get an aftermarket MAF or just the same one? I'm running a tenzo R full system cold air (sits behind the wheel for those who dont know) JDM header downpipe and exhaust. I'm getting sick of looking at the check engine light. any ideas on selection?

[ACE-tC]

Hey people i tried looking for this subject on the site but didn't find it and i'm not sure if this goes here but I have a question.

So i went to have my codes read and basically they told me to get a new MAF sensor. I was also told to just get the same model and all that stuff but my question is and from what i've heard should i get an aftermarket MAF or just the same one? I'm running a tenzo R full system cold air (sits behind the wheel for those who dont know) JDM header downpipe and exhaust. I'm getting sick of looking at the check engine light. any ideas on selection?

also i should mention i have no cat's in my car so i dont know if that makes a difference in my choice?

[CadenceScion]

also i should mention i have no cat's in my car so i dont know if that makes a difference in my choice?

I would like to start off by saying have you tried to clean your MAF sensor first? If you are going to replace it, buy one that is made for your car and I don't think the brand matters. Secondly, no CAT's is a bad idea. Your losing necessary backpressure and probably losing compression. I would highly suggest getting an aftermarket High-Flow CAT from Magnaflow, CatCo or wherever. Deleting the CAT's may also be causing the CEL and won't pass most states strict emissions laws. I don't know how your exhaust sounds, but I would also suggest getting a spiral flow resonator from Moroso or one from Magnaflow to even out the tone and cancel out bad tones. Furthermore helps w/ cutting down on rasp.

I forgot to mention that since you have a header, you'll need a anti-fouler/CEL eliminator to get rid of that annoying CEL. It will tie into your o2 sensor.

[ACE-tC]

I would like to start off by saying have you tried to clean your MAF sensor first? If you are going to replace it, buy one that is made for your car and I don't think the brand matters. Secondly, no CAT's is a bad idea. Your losing necessary backpressure and probably losing compression. I would highly suggest getting an aftermarket High-Flow CAT from Magnaflow, CatCo or wherever. Deleting the CAT's may also be causing the CEL and won't pass most states strict emissions laws. I don't know how your exhaust sounds, but I would also suggest getting a spiral flow resonator from Moroso or one from Magnaflow to even out the tone and cancel out bad tones. Furthermore helps w/ cutting down on rasp.

I forgot to mention that since you have a header, you'll need a anti-fouler/CEL eliminator to get rid of that annoying CEL. It will tie into your o2 sensor.

ok i cleaned it and after the 3rd day (today) the check engine light is back on.... looks like im stuck buying another one

[CadenceScion]

Well bro it was worth a try. I hope the new one works better for you and no more CEL.

[navylife59]

What is the DTC (code) that was scanned? It could be as simple as the o-ring on the MAF is kinked or sensor is dirty (use CRC MAF cleaner). Really need that code.

Engine compression is a mechanical function of piston stroke, combustion chamber size (piston head, head cylinder pocket, etc). Exhaust has nothing to do with it. I believe that you were thinking of exhaust scavaging which is a function of exhaust tuning, backpressure, cam profile, valves, etc. A turbo or flat out race car that sees mostly high RPM's is the only thing out there that benefits from zero backpressure.

[ACE-tC]

What is the DTC (code) that was scanned? It could be as simple as the o-ring on the MAF is kinked or sensor is dirty (use CRC MAF cleaner). Really need that code.

Engine compression is a mechanical function of piston stroke, combustion chamber size (piston head, head cylinder pocket, etc). Exhaust has nothing to do with it. I believe that you were thinking of exhaust scavaging which is a function of exhaust tuning, backpressure, cam profile, valves, etc. A turbo or flat out race car that sees mostly high RPM's is the only thing out there that benefits from zero backpressure.

ok so the code is P0420
on the description it says:
-catalyst efficency low-bank 1 (explanation: oxygen sensors monitor the catalytic converters ability to store oxygen) i dont have any cats
probable cause:
- catalytic converter defective
- engine misfire or running condition
- large vacuum leak
- engine oil leakage into eshaust-valve guide seals, piston rings

[ACE-tC]

ok so the code is P0420
on the description it says:
-catalyst efficency low-bank 1 (explanation: oxygen sensors monitor the catalytic converters ability to store oxygen) i dont have any cats
probable cause:
- catalytic converter defective
- engine misfire or running condition
- large vacuum leak
- engine oil leakage into eshaust-valve guide seals, piston rings

one more thing i should mention this started happening a couple days ago but once i turn the car on if i take off right away mycar shuts down/dies any input on that?

[ACE-tC]

I would like to start off by saying have you tried to clean your MAF sensor first? If you are going to replace it, buy one that is made for your car and I don't think the brand matters. Secondly, no CAT's is a bad idea. Your losing necessary backpressure and probably losing compression. I would highly suggest getting an aftermarket High-Flow CAT from Magnaflow, CatCo or wherever. Deleting the CAT's may also be causing the CEL and won't pass most states strict emissions laws. I don't know how your exhaust sounds, but I would also suggest getting a spiral flow resonator from Moroso or one from Magnaflow to even out the tone and cancel out bad tones. Furthermore helps w/ cutting down on rasp.

I forgot to mention that since you have a header, you'll need a anti-fouler/CEL eliminator to get rid of that annoying CEL. It will tie into your o2 sensor.

cadence i just saw this last part of your post what exactly is a anti-fouler/CEL eliminator and would you happen to know how much it is and where i can get one? also install?

[ACE-tC]

I would like to start off by saying have you tried to clean your MAF sensor first? If you are going to replace it, buy one that is made for your car and I don't think the brand matters. Secondly, no CAT's is a bad idea. Your losing necessary backpressure and probably losing compression. I would highly suggest getting an aftermarket High-Flow CAT from Magnaflow, CatCo or wherever. Deleting the CAT's may also be causing the CEL and won't pass most states strict emissions laws. I don't know how your exhaust sounds, but I would also suggest getting a spiral flow resonator from Moroso or one from Magnaflow to even out the tone and cancel out bad tones. Furthermore helps w/ cutting down on rasp.

I forgot to mention that since you have a header, you'll need a anti-fouler/CEL eliminator to get rid of that annoying CEL. It will tie into your o2 sensor.

would this work?
Universal Mechanical O2 Sensor CEL Eliminator Fix OBDII - eBay (item 300422382282 end time May-08-10 12:02:16 PDT)

[CadenceScion]

I know of some people who have bought CEL eliminators off of Ebay and they worked fine, and others went through the autoparts store or even Summit Racing/Jegs. I am not positive if the CEL eliminator is plug and play or it needs to be wired directly. IMO you shouldn't have any issues either way and it will take care of the annoying CEL.

[ACE-tC]

I know of some people who have bought CEL eliminators off of Ebay and they worked fine, and others went through the autoparts store or even Summit Racing/Jegs. I am not positive if the CEL eliminator is plug and play or it needs to be wired directly. IMO you shouldn't have any issues either way and it will take care of the annoying CEL.

awesome thanks. what im afraid of is, is there a real problem or is it just because of all the upgrades that the CEL is going off you know...

[CadenceScion]

awesome thanks. what im afraid of is, is there a real problem or is it just because of all the upgrades that the CEL is going off you know...

Sometimes its because there is an actual problem, but in your case I believe its because you upgraded your whole exhaust system, like the header for example. Some headers cause CEL's and others don't, plus I have talked to other Scion tC owners on another site that have experience the same issue as you. Get the CEL Eliminator and you'll be very happy you did. I can't remember if you installed your exhaust or a shop did it, but if a shop did it, they should've known better that you'd need a CEL Eliminator, or they didn't care as long as they got paid.

[ACE-tC]

Sometimes its because there is an actual problem, but in your case I believe its because you upgraded your whole exhaust system, like the header for example. Some headers cause CEL's and others don't, plus I have talked to other Scion tC owners on another site that have experience the same issue as you. Get the CEL Eliminator and you'll be very happy you did. I can't remember if you installed your exhaust or a shop did it, but if a shop did it, they should've known better that you'd need a CEL Eliminator, or they didn't care as long as they got paid.

awesome thanks man. I actually did it alongside witha friend who works on cars but he didnt mention an eliminator just to get a ne MAF sensor.

[CadenceScion]

I am sorry but your friend told you wrong and you have no need to replace your MAF sensor unless its bad. As I said and I believe Navy told you as well, its the o2 sensor that is giving you the issue and w/ the header, so by getting the CEL eliminator will take care of the CEL. I am not saying your friend doesn't know what he's talking about, but I see a lot of friends doing work on other peoples cars that have no idea what their doing and end up screwing something up. No offense, but I take my tC to someone who I know I can trust and has a ASE certification, not some joe down the street.

[ACE-tC]

I am sorry but your friend told you wrong and you have no need to replace your MAF sensor unless its bad. As I said and I believe Navy told you as well, its the o2 sensor that is giving you the issue and w/ the header, so by getting the CEL eliminator will take care of the CEL. I am not saying your friend doesn't know what he's talking about, but I see a lot of friends doing work on other peoples cars that have no idea what their doing and end up screwing something up. No offense, but I take my tC to someone who I know I can trust and has a ASE certification, not some joe down the street.

where do i install the CEL eliminator on the header or exhaust system o2 sensor?

[CadenceScion]

where do i install the CEL eliminator on the header or exhaust system o2 sensor?

You would install the CEL Eliminator on the bank 1 o2 sensor, the one closest to the engine/header/exhaust manifold. I would also check online/google just to make sure, but I am almost positive I am correct.

[ACE-tC]

You would install the CEL Eliminator on the bank 1 o2 sensor, the one closest to the engine/header/exhaust manifold. I would also check online/google just to make sure, but I am almost positive I am correct.

oh ok the one under the car on the exhaust system then. sweet thanks man. i assumed thats where it goes cause i never saw one on the header itself

[ACE-tC]

does anyone know if the o2 sensor on the exhaust is an 18mm fit? the CEL eliminator i want to get on line will only fit an 18mm

[CadenceScion]

does anyone know if the o2 sensor on the exhaust is an 18mm fit? the CEL eliminator i want to get on line will only fit an 18mm

I can't recall what header you said you were running, I think you said Weapon-R, anyhow, call up the company that makes your header and ask them what size you need or if they sell one that works.