What fuel additive is o2 & cat converter safe?

[leftlane]

I just realized seafoam is not advertised as cat converter safe. It only shows to be o2 sensor safe so using this in my tank and crankcase to clean the engine may have damaged the cat converter which may be causing my low mileage.

What fuel additive/engine cleaner is safe to use in vehicles that wont harm o2's or the cat converter?

 

[SrDriver]

First thing I would do is spend a few Dollars for the simple things like a new PVC Valve which should only cost a couple of bucks and have a alignment done along with maintaining the correct tire pressure.

I check the tire pressure a couple of times a month before vehicles are driven in the morning. They call for 35 PSIG and I run around 37. Picked up a air compressor some years ago.

Depending on mileage, spark plug wires, plugs, new air filter too may help you get better fuel economy.

I have used Lucas UCL fuel treatment @ the rate of about 2 - 2.5 oz per 10 gallons of gasoline for years with good results.

I carry the small bottle which I refill about half way from a larger container which saves money and add it just before pumping fuel so it gets mixed up good.

 

[Pablo]

Originally Posted By: leftlane
I just realized seafoam is not advertised as cat converter safe. It only shows to be o2 sensor safe so using this in my tank and crankcase to clean the engine may have damaged the cat converter which may be causing my low mileage.

What fuel additive/engine cleaner is safe to use in vehicles that wont harm o2's or the cat converter?


Amsoil PI: Amsoil PI LINK is 100% O2/cat safe and strong enough to really clean.

 

[SrDriver]

Pablo sounds like he has some other issues causing poor fuel economy?

 

[Pablo]

I was merely answering the title question, but indeed I doubt one application of Sea Foam would damage a cat to that extent.....indeed look elsewhere for the MPG drop and if you suspect cat damage get a proper diagnosis.

 

[leftlane]

These cat converters are prone to going bad anyway on the 01 corolla so I doubt it was solely because of the seafoam since I have smelled sulfur out of the exhaust for years. They warranty the cats up to 80k miles because of it. I also used b12 in the tank and crankcase so that may have contributed also since Ive seen on here that theyre no longer listed as cat converter safe.

Ive already installed a new oem pcv, new oem plugs properly gapped(the 01 has coils, no wires) with the ECU reset, recharged the air filter, cleaned the maf with crc maf cleaner, alignment was checked and is good, tires are up to proper pressure however I believe one pulls so I that could be contributing to low mileage although the low mileage started before I had that tire.

I just bought oem o2 sensors since its time to replace them so I'll install them and see if that helps. If not then a lot of people have had success with improving mileage in their corollas by replacing the temp stat, and if that doesnt work then I'll get a new cat converter since its time to replace that anyway.

 

[Quest]

Don't forget that there are gas out there that are not certified as "top tier" and may come with additives such as MMT (as octane booster) that will slowly/surely damage your cat.

Also: if your car burns a bit or oil or you opt for oder API specifications that contains higher ZDDP within, your cat will get poisioned as well.

Normally, cats don't go bad so easily so long as (a) your engine isn't burning huge amounts of oil; (b) you are not using MMT-laden gas; (c) your PCV valve and what-not are working properly; (d) you are not intentionally throwing in things that are not deemed sensor/cat safe such as 2T oil (ash), non sensor-safe FI cleaners, etc.

Q.

 

[leftlane]

I used valero gas for a short while which I believe is not top tier if I remember right but now I only use chevron regular so no top tier concern there, and no mmt concern that Im aware of. The techron in their gas should be no concern correct?

These older corollas do burn oil which I didnt know at first so I didnt always keep it topped off as I should have which caused varnish buildup so that couldve contributed along with the gunk building up in the cat converter after using seafoam and b12 to clean the varnish out of the engine, but I do keep the oil topped off now and I use SL/SM oils only(SJ+ required).

 

[[RT] ProjUltraZ]

my big 3" hi-flow cat was rattling so i dropped it and gutted it. Despite several seafoam, FP+ and regular fuel inj cleaner tx, the honeycombs still looked light brown and no build up. It only had about 25,000 miles on it but i do drive the Z28 hard and autox too. it sees redline 1 or more times per week

but the two honeycombs themselves had zero buildup.

 

[chevrofreak]

I've run all kinds of stuff through my engine, from small amounts of synthetic motor oil to kerosene, IPA and ATF to 2 stroke oil to Seafoam, and during a recent exhaust system modification I looked into my cats and the honeycombs looked brand new.

My car is a 96 ex-police Crown Victoria with over 120K on it.

 

[47HO]

Your results don't bode well for the cat poisoning theory caused by a few ppm of ZDDP.