Recently noticed my car running rich i guess, when i crank it sometimes i can smell the gas fumes like raw gas or something. What can this be coming from? O2 sensor? dont have any codes but 0420 cat converter. 2002 i35.

 

O2 or maf. Since there's no O2 code and being that the maf is notorious for going south and never has a code... But it should smell rich at startup. If your fuel economy is normal, then I'd say it's fine.

Better get rid of those cats if you still have 'em

Time to install a wideband Imagine if every car came with AFR readout from the factory. People would know when maf or O2 is bad, but nooooooo, we wouldn't want them to be able to fix it. Or oil pressure, actual temp, etc. ******** want you to ruin it.

 

yeah fuel economy is good after replacing the vent control valve and charcoal canister. I took the maf out and cleaned it then did the pedal dance. Going to replace the cats next week as i get the rotten egg smell sometimes. Just it sometimes smells like raw gas at startup once the cars been running for a while. Rear cat rattles but its getting replaced, and i dont drive the car but 3 times a week.

 

Time for headers if you're going to replace anything

 

Headers may be next i i just dont want the loudness, and once the shop replaces the rusted bolts from the front of the exhaust, then i can work on the exhaust myself the next time. But ill prob look at some prices for the headers lol. What is the rear main 02 sensor called, is ebay a good place to buy it from, may go ahead and do that since the exhaust is gonna be worked on.

 

If you leave the stock catback it's still sissy quiet
Headers plus gutted rear cat =
At the very least gut the precats.

You want bosch sensors, so none of that knock off crap. They're just called upstream or primary. The universal fit ones are cheaper, but I haven't had good luck with them (sensor is different looking, so maybe that's why).
Here's the cheapest exact replacement I found http://www.ebay.com/itm/BRAND-NEW-BO...VVrqBS&vxp=mtr

 

Well if its still gonna run quiet then I may consider headers later on, thanks for that info on o2 sensors, check engine light came on and was flashing po300. Im thinking coil may be bad but cant tell which one

I believe the misfire is on bank 1, gonna try to check it out in the morning

still getting the po300 but it didnt start until i sprayed my maf with crc cleaner, i hav an extra one sitting around from a 5th gen. So im gonna see if that solves the problem. Check engine light flashes/ and or it misses when im at highway speeds or midway throttle when the vias kicks in, its super slow to get up to speed at times. Gonna swap out the maf and see if thats the problem. If not I know its exhaust related, headers are starting to look pretty good right now. I did unbolt the main cat to see if it was clogged, which is the only part of the exhaust that isnt rusty.

 

Is there a preferred recommendation on a Wideband?

 

whats a wideband?

 

you should test them with a cheap voltmeter to see if there in spec. i believe 1.49-1.60 is acceptable. i forget which pins will give you the reading but its very easy. there is a diy on here somewhere im just on mobile curently.

 

I have a volt meter but dont know what setting to use to test them. I know sometimes i get a rich condition at startup, and the car is kinda slow. Sometimes it runs good and then sometimes it feels clogged up. But i dont know what can be causing the rich condition other than 420.

 

Ok lets me see here, I used the 20k setting to test it but you can flip through the different ohm settings if you do not see proper numbers. Check for vacuum leaks after the MAF and check that your exaust has no leaks. Not a single hiss. Sometimes a stuck injector can dump fuel but that's rare. A weak spark would not properly ignite all the fuel/air charge and in return the o2 is picking it up as rich. That same charge can destroy the cats if you have driven like that for a while, and that's even if the coils are the issue. When did you last do plugs/ what brand?

 

I use this, perfectly fine.

http://www.zeitronix.com/Products/Zt-3/Zt-3.shtml


130$ for the entire package w/readout. No recording capabilities, but I never used them that much when I had the PLX WB. The ZT-3 is affordable and does all we need or at least for me.

 

I did all 6 plugs last year in september, but didnt really drive the car very much until jan. I used NGK platinum alloy at least thats what the box said and got them from pep boys for around $25 for all 6. The only thing i can think of is the number 5 spark plug which had a bunch of oil in the tube. I didnt change that one since i put in a new valve cover. Each of the coils when unplugged make a difference in how the engine runs. Im thinking the exhaust is clogged somewhere as the car is gotten slower when trying to get on the highway. Since ive had it ive only put maybe 5k miles on the car. Im going to replace the rear pre cat for now, at least let the shop do it in the next few days, and see if i get the power back. . I think its running in limp mode though. in

 

Well it seem I had a vacuum leak at the pcv valve hose, and the breather hose was cracked in half and I didnt kno it.

 

Unless it's so bad it causes a misfire, it doesn't affect anything. Cracked hoses don't leak much.

 

Well while i was taking my intake manifold off today to change one of the rear bank spark plugs, and to see if i could access the rear engine mount from above, I found a cracked air intake hose/ I guess thats what the hose is called between the throttle body and maf. Ive never removed it before to take a look at it, always just slid it off and screw it bak on. The thing had a huge hole in it at the bottom i could literally stick my hand inside. And if i didnt take it off today, i would have never known.

 

Yes, the intake boots degrade and will rip. Usually they only tear when being touched (or maybe shot motor mounts LOL).

 

So that means there was air entering that was not being detected by the maf the entire time. I usually remove my intake but never really unhook that hose i just unscrew it from the throttle body. Well off to the salvage yard in the morning to see if i can find another one. At least until i order a new one i guess.

 

I have seen many with duct tape lol.

As long as you find one that's soft with no cracks, I wouldn't worry about buying a new one.
I would junk it all. Custom intake ftw

Odd issue for a 5.5 (3.0s get really hard and crack), I think, but at least you solved the mystery.

 

Well looked in the junkyard today and found one on a 3.0 but it wouldnt fit. Dealer wants $52 amazon has it for $20. Tried to put duct tape around it but its got multiple holes in it.

 

Gonna try to attempt to pull the front cat off tomarro, got myself a torque wrench,pb blaster, and soaked the bolts a few times, or at least pull the front cat with the y-pipe attached. I managed to get one top bolt off, hoping that that others dont break off or im screwed lol.The front heat shield managed to somehow loosen itself. Only problem i may run into is the bank 1 pre cat bolts on the y-pipe looks like they are frozen stuck.