When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have two codes
1. P0104 Maf sensor circuit intermittent
2. P0430 CAT bank 2 efficiency below threshold
Mileage on my car is 118000 roughly
i cleaned Maf sensor it helped with rough idle but made the ride a bit smoother but still get maf sensor code
i have been clearing codes since past couple of months. CEL keeps coming back.
I noticed CEL wont come for a long time if I let the car heat up a lot before driving it above 2000 rpm.
If i hit above 2000rpm before engine is heated up i will right away get CEL.
I went to Lexus/Toyota dealership for CEL diagnostics
was yold that both CATs need to be replaced.
i know they are trying to make 4000$ And feel they are trying to fool me as CATs wont go bad at such low mileage plus them saying both are gone makes me suspicious.
i have attached freeze frame data if some experienced person can help me out here
The P0430 is very likely an exhaust leak in the area of the Y-pipe, perhaps under the heat shield. What happens is that hot exhaust gasses leak out upstream of the secondary cats, which takes them longer to light off -- if they aren't lit off by the time OBD2 diagnostic runs (about 10 minutes after a cold start), you get the P0420 or P0430 code. The dealer will replace the entire section of exhaust at a cost of $2000+, but a good exhaust shop should be able to cut out the corroded section of pipe and fabricate new for a fraction of that.
The P0430 is very likely an exhaust leak in the area of the Y-pipe, perhaps under the heat shield. What happens is that hot exhaust gasses leak out upstream of the secondary cats, which takes them longer to light off -- if they aren't lit off by the time OBD2 diagnostic runs (about 10 minutes after a cold start), you get the P0420 or P0430 code. The dealer will replace the entire section of exhaust at a cost of $2000+, but a good exhaust shop should be able to cut out the corroded section of pipe and fabricate new for a fraction of that.
i will try to get in touch with some exhaust shop to see if they can spot it out.
btw i dont have any symptoms of bad CAT like loss of power or bad smell at exhast although i do smell gas from my exhast.
Yup Bichon is likely right. Exhaust leak on mid-pipe under the heat shielding. I was getting the same codes, P0420 - P0430, knew i had a leak as it sounded like a dump truck. Took to my local mechanic, cut out old pipe and welded new pipes from behind downstream O2 sensors to just before the secondary cats on both sides for about $400 all in. Codes have never come back since. It's a common issue on the 2IS's, especially it areas that see snow/salt.
As far as the MAF sensor code, you could try putting in a new MAF sensor, they arent all that expensive.
Yup Bichon is likely right. Exhaust leak on mid-pipe under the heat shielding. I was getting the same codes, P0420 - P0430, knew i had a leak as it sounded like a dump truck. Took to my local mechanic, cut out old pipe and welded new pipes from behind downstream O2 sensors to just before the secondary cats on both sides for about $400 all in. Codes have never come back since. It's a common issue on the 2IS's, especially it areas that see snow/salt.
was getting the P0430 code too every 3 or 4 months. Cleared with a reader device but exhaust was getting noisy so took to an independent shop on the way home. Sure enough small corrosion hole on top of exhaust pipe drivers side below the seat. Mechanic said the rest of the pipe was OK and better than an aftermarket new one, also an entire new Lexus pipe was expensive, so he clamped on a 3” long SS half tube piece, charged $65 and I was out of there in 45 minutes.
It’s kind of bad resorting to this kind of repair but it is a 10 yr old car and mainly for the kids’.
2010 Lexus is250 awd CEL
