Liqui Moly Pro-Line Throttle Valve Cleaner
Priced as of May 25, 2026
4.6(123 ratings)Buy on AmazonSaved to your guest loadout. Sign up to also save to your Cabinet (consumables) or Kit (tools you own).
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Prices may varySerious hazard — read before use
The manufacturer's Safety Data Sheet classifies this product with one or more GHS Category 1 health hazards — the most severe tier. The hazard statements in quotes below are the verbatim GHS language from the SDS, as required by OSHA's Hazard Communication Standard. The line under each statement translates the GHS classification into plain language.
- H304 “May be fatal if swallowed and enters airways.”
GHS Category 1 aspiration toxicity — thin, oily liquids can slip into the lungs if swallowed, causing chemical pneumonia.
If swallowed, inhaled, or splashed in eyes:
Call Poison Control immediately at 1-800-222-1222 (US, 24/7, free) and have the product container with you. Poison Control's standing guidance is to not induce vomiting after chemical exposure; they will direct first-aid steps based on the specific product.
About this product's hazards. This product's Safety Data Sheet uses signal word danger. Read the manufacturer's SDS and follow all safety instructions before use. CarCareTruth ratings translate the manufacturer's safety sheet. They do not replace the SDS or substitute for a hazard assessment specific to your task.
Health score is for adult use as intended, per the manufacturer's SDS. It does not model child ingestion, accidental spill cleanup, or off-label use. See the safety panel below for full hazard classification, and /disclaimer for the full editorial scope.
From the Safety Data Sheet
Full SDS ↗ (rev. 2024-06-03)GHS hazard codes are quoted from the manufacturer’s Safety Data Sheet. PPE tiers below translate those codes and the listed ingredient chemistry; they are not CarCareTruth recommendations.
EyesSituationalMfr. SDS §8 · 29 CFR 1910.133(a)(1) · GHS H319SkinRecommendedMfr. SDS §8 · 29 CFR 1910.138(a) · GHS H315LungsRequiredMfr. SDS §8 · 29 CFR 1910.1000 · GHS H351Ventilation—No PPE in published sourcesShow details for all categories ▾Hide details ▴
From the manufacturer’s Safety Data Sheet, Section 8
“H319 (eye irritation) present in SDS §2. Aerosol mist during spray application into a confined engine bay can cause temporary eye irritation on direct contact. SDS §8 specifies chemical goggles or safety glasses.”
— Liqui Moly
U.S. regulatory standard
29 CFR 1910.133(a)(1)
“The employer shall ensure that each affected employee uses appropriate eye or face protection when exposed to eye or face hazards from… liquid chemicals…”
ANSI Z87.1 (incorporated via §1910.6)
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
From the manufacturer’s Safety Data Sheet, Section 8
“H315 (skin irritation) confirmed in SDS §2. SDS §8 directs chemically resistant protective gloves. The aromatic-solvent-heavy formula causes defatting and dermatitis on repeated or prolonged skin contact.”
— Liqui Moly
U.S. regulatory standard
29 CFR 1910.138(a)
“appropriate hand protection when employees' hands are exposed to hazards such as those from… chemicals which produce an adverse effect on the skin or eyes…”
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
From the manufacturer’s Safety Data Sheet, Section 8
“DANGER signal word driven by health-tier H-codes (H304, H315, H319, H336, H351). H336 (narcosis) is the dominant inhalation pathway — headache, dizziness, and loss of coordination are documented acute effects from the SDS classification. SDS §8 specifies an approved respirator when exposure limits are exceeded; the H336 vapor profile in confined-space or low-ventilation use is the key driver. SDS precautionary statement P271 requires use in outdoor or well-ventilated area only.”
— Liqui Moly
U.S. regulatory standard
29 CFR 1910.1000; 1910.1200
“Each employer shall assure that no employee is exposed [in excess of the PEL]…”
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
The published Safety Data Sheet for this product does not specify ventilation protection for consumer use.
Workplace context
29 CFR 1910.134(a); 1910.1000
“the primary objective shall be to prevent atmospheric contamination [via] accepted engineering control measures (for example, enclosure or confinement of the operation, general and local ventilation…).”
Triggered by GHS H336 on the SDS.
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
PPE tiers translate the manufacturer’s SDS and U.S. regulatory standards. Not professional safety advice. How we report safety.
The Podium · Top 3 in Carburetor Cleaner
See the full ranking →This product ranks #10 of 11 in Carburetor Cleaner.Three above it ↓
CarCareTruth's Analysis
Last reviewed May 26, 2026
TL;DR Liqui Moly Pro-Line dissolves throttle-plate carbon and light varnish in a single pass — Amazon verified-purchase reviewers (4.6 stars, 123 reviews) confirm improved idle and cleared trouble codes on high-mileage units. Cat-safe and GPF-safe per the manufacturer; no explicit O2-sensor-safe claim on the product page or label. DANGER signal word backed by real chemistry: H304 aspiration hazard, H336 narcosis risk, and a Prop 65 warning for naphthalene. Lungs PPE is chemistry-mandated for any low-ventilation use.
What it is and how it performs
This aerosol dissolves gum, carbon, and oily deposits from throttle bodies and carburetor bores via a flex-hose nozzle in 1–3 second bursts on a running engine. No O2 codes or surface damage reported in the Amazon review corpus. Best on moderate-to-heavy deposits in accessible passages — heavily lacquer-varnished carburetors from long storage typically need an overnight dip.
Who should buy this — and who should skip it
Right for a home mechanic or shop tech equipped for professional-grade chemistry: respiratory protection, gloves, and a well-ventilated workspace. The cat/GPF-safe claim supports modern gasoline engines. Skip it for GDI intake-valve carbon — that requires a dedicated intake cleaner or walnut-blast service.
Safety and environmental impact
SDS (Rev 2024-06-03): DANGER — H304 (aspiration hazard; do not induce vomiting if swallowed), H336 (narcosis from vapor inhalation), H315/H319 (skin and eye irritation), H351 (suspected carcinogen; naphthalene Prop 65 warning confirmed in SDS §15.3 at <0.5%). Flash point −17°C: extremely flammable aerosol. H401/H411: toxic to aquatic life — keep out of storm drains. No CARB compliance claim on file. Estimated absolute VOC above 550 g/L.
Frequently asked questions
Is Liqui Moly Pro-Line Throttle Valve Cleaner safe for catalytic converters?▾
The manufacturer states the product is suitable for engines 'with or without turbochargers, catalytic converters and particulate filters (GPF).' That cat-safe claim is on the Liqui Moly US product page for this SKU. The SDS does not make an O2-sensor-safe claim explicitly.
Does this product carry a Prop 65 warning?▾
Yes. SDS §15.3 (Rev 2024-06-03) states: 'This product can expose you to Naphthalene, which is known to the State of California to cause cancer.' Naphthalene is present at <0.5% per SDS §3. This is a real warning, not a precautionary listing.
Can I use this on a GDI engine?▾
For the throttle body itself, the manufacturer states compatibility with gasoline direct-injected engines. The core carbon problem on GDI engines is intake-valve deposits that a throttle spray cannot reach — no port wash on GDI. For intake-valve carbon on GDI engines, a dedicated intake cleaner or walnut-blast service is the appropriate solution.
Is this product CARB compliant?▾
No CARB compliance claim appears in the SDS (Rev 2024-06-03) or on the Liqui Moly US product page. The formula is acetone- and aromatic-naphtha-dominant with an estimated absolute VOC above 550 g/L.
From the manufacturer
Marketing copy from Liqui Moly, via Amazon. Not editorial.
- •Rapid and effective cleaning and degreasing
- •Cleaning without dismantling
- •Simple to use and economical
- •Rapid and effective cleaning and degreasing
- •Cleaning without dismantling
- •Simple to use and economical
- •Rapid and effective cleaning and degreasing
- •Cleaning without dismantling
- •Simple to use and economical
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Manufacturer images
Manufacturer specifications
- Brand
- Liqui Moly
- Item Form
- Liquid
- Scent
- Unscented
- Specific Uses For Product
- Throttle Valve
- Material Feature
- Clean
- Surface Recommendation
- Gasoline
- Contains Liquid Contents?
- Yes
- Brand Name
- Liqui Moly
- Global Trade Identification Number
- 04100420202100
- Manufacturer
- Liqui Moly
- Model Number
- 20210
- Part Number
- 20210
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Top Amazon review
↗External — Amazon's most-helpful review for context.
This cleaner is awesome worth every penny.
Used as instructed for throttle body cleaning. My vehicle is a 2006 Toyota Camry with over 170,000 miles had a service engine code PO113 (air intake Temp. High). I cleaned the filter and followed up with this product on the air intake tubing of the throttle body. Gave it two good squirts while someone helping me maintain the engine running. After that reassembled the filter and reset the diagnostic code and done. Engine idles better and code is gone. I would highly Recommend It.