LX470/100 Exhaust Manifold

[LX1L]

I have 2003 Lexus LX470 with 370,000 miles on it. I have recently replaced the cats and put new coil packs on it. Since then some of the coils have gone bad and I had to redo them. The shop which did the cats now is warrantying the cats because they say the cats have gone bad. In the process, they said my exhaust manifold maybe bad which created the problems with the cats and coils. They are suggesting replacing the exhaust manifolds. Does that sound right?

Please let me know if anyone else has had an issue similar to this and what you did. Thank you.

 

[MongooseGA]

Generally the first sign of a bad manifold will be a ticking at cold start, progressing into a ticking all the time. I hadn't read of or seen bad manifolds causing problems to the coils but I'm not savvy enough to rule it out.

The manifolds going bad were a common-ish issue on the older models, I thought pre-03. If you don't hear ticking, I'd do some more research before determining it's the manifold. The parts aren't crazy expensive (still not cheap) but the labor is a bitch. Or expensive, depending on who does it.

 

[uzj100]

This does not sound right. Is it throwing any codes? Are the O2 sensors in good shape?

And if you need manifolds get DT headers (Manifolds) and give yourself +15 hp gain on your truck.

I would go to a Toyota dealer and get a second opinion.

And if you are near ACC Toyota, take it to them.

 

[jsigone]

it's a 10hr job on the headers so take that into consideration when they quote you for labor. I'd throw doug thorley headers in there for $700 when/if I get annoyed by my ticking leaks.

Less air going through the cats would not likely cause them to go out of warranty

Cheap coil packs go out faster than say if they used OEM parts. OEM coils are also much more money. One OEM coil is the price of 8 cheaper ones. $80 per OEM

90080-19027 - Toyota Parts Deal:,

 

[LX1L]

It was throwing an 02 code as well as codes for the 1, 4 and 8 coil.

 

[MongooseGA]

Who's your tech? You're not far from me, I have a guy I wholly recommend in Woodstock. Way closer to you than ACC and a hell of a lot cheaper, too. And you won't have to schedule weeks in advance.

 

[LX1L]

Who's your tech? You're not far from me, I have a guy I wholly recommend in Woodstock. Way closer to you than ACC and a hell of a lot cheaper, too. And you won't have to schedule weeks in advance.

A Goodyear shop here in Cartersville sent me to a local muffler shop in Cville for the Cats, the muffler shop warrantied the bad cat and says it is most likely a crack in the manifold causing the code and CAT problem. Can you give me the guys info in Woodstock.? I was thinking of going to ACC, but I am all about saving money, plus Woodstock is way closer. Thanks.

 

[DTCsk8er]

There are ways to prove CATs going bad.. heat signature, and also a cool trick using propane and observing the o2 pre/post signals.

If you dont hear the tick tick tick like most of us (myself included), you likely don't have an exhaust leak. Also, there are probably countless cruisers with these leaks that don't throw codes or ruin o2/cats. Mines been ticking since I purchased it, 35k miles ago, all the time.

 

[LX1L]

I have heard the tick, tick, tick for years when I initially start the engine, but it goes away. Honestly, until recently I thought I had a ticking valve at startup.

 

[SJWantsADiesel]

I had both manifolds replaced with OE parts about 10-12k miles ago (210k miles on the odometer). Now, the passenger side is leaking again. Before I have it replaced, because it annoys the hell out of me, is there anything else I should have checked that might be causing premature failure of manifolds?