cel help please

Izapyou · 06-23-2009, 12:47 AM

alright im at my breaking point with this car. either i fix it or sell it i love the car and it is not what i want to do. ok for like the last 3 months i keep getting this damn code p0133 past and pending. i know what i means , but im confused. ok ive changed every ground bolt in the car. i changed the manifold gasket. i changed the flange gaskets. i changed the upstream 02 a million times. i did the test off the hyundai service manual online for this code, and still get mixed results more then a volt drop across the terminals, but no ohms in the neg cable. i changed the flex part out of the exhaust. what else could it be? the dealerships and people i know with hyundai say its an exhaust leak even super minor, but idk. my friend thinks its an ecu issue. how do i figure this out please i need guidance. i do get a good span of milli-volts of 100-900. also when the keys off the milli-volts it good at 430. weird thing is the car when you resest the light it can trip another code with the map sensor circuit air temp out of range code. also when i reset the light the 02 is crazy fast then slows down. i need advice please.

g4ebguysite · 06-23-2009, 12:59 AM

Have u checked resistance through the wires that go to and from the sensor not just the sensor itself.

It could also be the computer.....doubt it but u never know.

The sensor works.... so apparently the problem is in the wire to the computer. check the voltage @ the computer... u will need a schematic..... and also the comps under the steering wheel area i think. ...being the 02 is nothing more then a resistance based sensor...it seems ok...but the computer isnt doing its job. Possible u have a vacuum leak?

Izapyou · 06-23-2009, 01:09 AM

car runs great, no vaccum leak. how do i check the resistance on the wiring? also on the ecu? idk what where to go with this car. its hasnt given me a problem til now. its weird it also have an evo fusion header setup that elminates the cat, but theres no code for it. als i wonder about the ecu because it never told me there was a problem with the evap system. do the ecu for hyundais have a transmission control module built in?

g4ebguysite · 06-23-2009, 01:27 AM

U take a ohmmeter...and i dont wanna wip out my 800 page Computerized engine control book so ill leave it to u. But not having the cat on is the definate reason why the 02's are acting weird for the cat helps burn up some of that left over oxygen cuz fuel gets trapped in the cat and then burns off with the oxygen....Leaning out the mix.... but with no cat u deff will have some funny 02 and MAF-MAP variations in operation.... i would say your car is completely fine..... if u put the CAT back on i gurantee all the trouble would go away...i actually wanna remove mine

usherly · 06-23-2009, 05:31 AM

no cat is giving you the funny reading for the downstream o2 sensor

as g4eb said the cat uses unburnt oxygen to convert noxious carbon monoxide and incomplete combusted NOx emissions into carbon dioxide and full NOx emissions
without a cat - there is no registered drop in o2 levels across the two o2 sensors and so it spits a code thinking something is wrong

Izapyou · 06-23-2009, 08:02 AM

heres the weird thing 2 ive had this kit on my hyundai for 2 years and just started having this problem. also when i had it checked by a ase master mechanic he couldnt understand why the hyundai had 2 different voltage from the upstream and downstream 02 like the car had a cat. do you think that an exhaust leak prior to the downstream 02 still could cause an increase the oxygen count for the upstream 02 throwing this code? this cars ecu is weird never had an evap code come up but had to replace it by hyundai making me worry about an ecu problem. i know where i could get one from a lc, but its for a stick and idk if it will work for the automatic 03 gt. heres another thing too, the car will pass its scans for a while then the code comes back. i wish i knew how to get an evo fusion flex pipe but there on back order. i appreciate the help i look forward to more.

Izapyou · 06-23-2009, 08:12 AM

hey sorry forgot something, ok for starters i thought the downstream 02 only cared about the converter not the upstream 02. if i put one on (converter) where would it go, ive got an evo fusion 4-2-1 manifold on it so the converter would still be down away from the upstream 02 so would that still help? thanks for the advice in advance.

g4ebguysite · 06-23-2009, 10:32 AM

The convertor would go before the downstream but after the upstream....so like right after the flex pipe. if u dont have a flex then right off the header pipe or a inch or 2 down more. I woul djust leave it off..... U deff get better performance without one... they are a large restirction.... Il use the delorian as example.....it made 170hp with no cat and that was good back then.......they put a cat on it so they could sell it in USA.... went to 140..... it made one sad car to drive i bet.

The Back 02 usually doesnt change much... it likes to stay close to a range..... and the whole point of the rear 02 sensor is to measure catalyst effieceny but with no cat it will go crazy and think someting wrong.... the front one will then be saying MY COMBUSTIONS 02 is perfect mUTHA FU**** and the rear would say *sorry sir no its not* and then all hell breaks loose.... the injectors throw as much fuel in as possible... increasing exhaust temps...the CAT blows up and shoots shrapnel through your oil pan.... releasing your synthetic oil....which then starts to not lubricate the cam......as the cam turns and turns it locks up and the cam gear shears off..... then the piston comes up and hits your valves bending them actually makeing a backfire through the intake which blows off your short ram through the front fender....hitting a police car.... not to mention a rod went through the block and hit your subwoofer power wire.... shorting it... which then blew your amp and subs in a wiff of smoke because u didnt put a fuse on the power wire... after all that u put it in park after moving 2 feet out of your driveway.

**thegrim** · 06-23-2009, 01:16 PM

what is your entire mod list of anything performance on the car?

Izapyou · 06-23-2009, 02:48 PM

the list of mods factory its a gt so the ground effects carbon fiber interior ngk iridium spark plugs 8.5 wires euro k&n intake system lowering springs hids yellow fog lights kyb struts evo fusion strut tower braces evo fusion header system custom "cat" back system. ok heres the deal idk what to do i dont want to put the stock parts back on nor do i want to take off the aftermarket exhaust. i need the evo fusion flex pipe with gaskets but have had no luck getting it. i want to eliminate the possible exhaust leak from the equation for this problem. also what is the ohms readout for the harness for the 02 sensor like what setting should i test at and the specs? its weird ive got correct voltage key on engine off and while the engine is running voltage spans 100-900. so either its still the exhaust leak or ecu or idk. the 02s from hyundai are bosch so its not them. i still appreciate the help and need more guidance.